Calculation device, detection system, molding device, calculation method, detection method, molding method, calculation program, detection program and molding program

Abstract

This invention provides a technology that contributes to suppressing the occurrence of manufacturing defects in a three-dimensional object manufacturing device. [Solution] A computing device used in a fabrication apparatus that fabricates a three-dimensional object from a solidified layer formed by heating a layered material layer created from powder material by irradiation with energy rays comprises a detection unit that determines the state of the material layer based on the shape of the formed material layer, and an output unit that outputs information regarding the state of the material layer determined by the detection unit in order to set the fabrication conditions of the fabrication apparatus.

Description

Technical Field

[0001] The present invention relates to an arithmetic unit, a detection system, a shaping device, an arithmetic method, a detection method, a shaping method, an arithmetic program, a detection program, and a shaping program.

Background Art

[0002] Conventionally, there has been known a three-dimensional object manufacturing apparatus that manufactures a three-dimensional object by laminating layers obtained by solidifying a powdery substance by the action of light or the like (for example, Patent Document 1). However, there is a possibility that defects may occur in the manufactured object.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] According to an aspect of the invention, there is provided a shaping system for shaping a three-dimensional shaped object composed of a solidified layer in which at least a part of an unmelted material layer made of an unmelted powder material is solidified by irradiation with an energy beam, the shaping system including: a light receiving unit that receives light from the unmelted material layer; and a shaping unit that shapes the three-dimensional shaped object under shaping conditions set based on information related to at least one of flatness, density, lamination thickness, and shape of the unmelted material layer obtained based on a light reception result at the light receiving unit, wherein the shaping conditions include an intensity distribution of the energy beam.

Brief Description of the Drawings

[0005] [Figure 1] It is a block diagram schematically showing a configuration of a shaping device according to a first embodiment. [Figure 2] It is a diagram schematically showing an example of a specific configuration and arrangement of a shaping optical unit included in the shaping device. [Figure 3]This diagram schematically shows an example of the specific configuration and arrangement of the optical unit for 3D printing in a modified example. [Figure 4] This diagram schematically shows the state of the molten pool on a material layer and its vicinity, which are created when laser light is irradiated onto the material. [Figure 5] This figure schematically shows an example of a temperature image corresponding to the generated temperature image data. [Figure 6] This diagram illustrates the process of determining sputtering from the generated temperature image data. [Figure 7] This diagram illustrates the process of determining Humes from generated temperature image data. [Figure 8] This diagram illustrates the relationship between the molding conditions, the basic conditions of power density, energy density, and temperature distribution, and the parameters related to those basic conditions. [Figure 9] This diagram illustrates the relationship between the molding conditions, the basic conditions of power density, energy density, and temperature distribution, and the parameters related to those basic conditions. [Figure 10] This is a flowchart explaining the process for handling real-time changes. [Figure 11] This is a flowchart explaining the process for handling real-time changes. [Figure 12] This is a flowchart explaining the process for handling real-time changes. [Figure 13] This flowchart explains the process for making changes during the subsequent layer printing process. [Figure 14] This flowchart explains the process for making changes during the subsequent layer printing process. [Figure 15] This flowchart explains the process for making changes during the subsequent layer printing process. [Figure 16] This flowchart explains the process for making changes during the subsequent layer printing process. [Figure 17] This is a schematic block diagram showing the main components of the molding apparatus in a modified example (2) of the first embodiment. [Figure 18]This is a schematic block diagram showing the main components of the molding apparatus and detection system in a modified example (3) of the first embodiment. [Figure 19] This is a schematic block diagram showing the configuration of the molding apparatus according to the second embodiment. [Figure 20] This figure schematically shows an example of the specific configuration and arrangement of the shaping optical unit in the shaping apparatus of the second embodiment. [Figure 21] This is a flowchart illustrating the process performed by the molding apparatus in the second embodiment. [Figure 22] This is a flowchart illustrating the process performed by the molding apparatus in the second embodiment. [Figure 23] This is a flowchart illustrating the process performed by the molding apparatus in the second embodiment. [Figure 24] This diagram schematically shows the cross-sectional shape in the ZX plane of a predetermined amount of powder material that is the target of pre-detection. [Figure 25] This is a flowchart illustrating the process performed by the molding apparatus in the second embodiment. [Figure 26] This is a schematic block diagram showing the main components of the molding apparatus in a modified example of the second embodiment. [Figure 27] This is a schematic block diagram showing the main components of the molding apparatus and detection system in a modified example of the second embodiment. [Figure 28] This is a schematic block diagram showing the configuration of the molding apparatus according to the third embodiment. [Figure 29] This figure schematically shows an example of the specific configuration and arrangement of the optical unit of the third embodiment of the 3D printing apparatus. [Figure 30] This is a flowchart illustrating the process performed by the molding apparatus in the third embodiment. [Figure 31] This is a schematic block diagram showing the main components of the molding apparatus in a modified example of the third embodiment. [Figure 32] This is a schematic block diagram showing the main components of the molding apparatus and detection system in a modified example of the third embodiment. [Modes for carrying out the invention]

[0006] -First Embodiment- The first embodiment of the fabrication apparatus will be described with reference to the drawings. In the following description, a fabrication apparatus that fabricates three-dimensional objects (three-dimensional fabricated objects) using a known powder bed fusion (PBF) method will be used as an example. Powder bed fusion (PBF) is also called powder sintering additive manufacturing (SLS). Furthermore, the fabrication apparatus is not limited to powder bed fusion (PBF), but may also be an apparatus that fabricates three-dimensional objects using other methods such as directed energy deposition (DED), material jetting, electron beam fusion (EBM), or fused deposition modeling (FDM). First, the configuration of the molding apparatus 1 will be explained with reference to Figures 1 and 2. Figure 1 is a schematic block diagram showing the structure of the molding apparatus 1, and Figure 2 is a schematic diagram showing an example of the specific configuration and arrangement of the molding optical unit 35 of the molding apparatus 1. For the purpose of facilitating understanding, the following explanation will be given using a Cartesian coordinate system consisting of the X, Y, and Z axes, as shown in Figures 1 and 2.

[0007] The molding apparatus 1 comprises a housing 10, a material layer formation unit 20, a molding unit 30, and a computing unit 50. The material layer formation unit 20 comprises a material supply tank 21 and a recoater 22. The molding unit 30 comprises a molding tank 31 and a molding optical unit 35. For the sake of explanation, the material layer formation unit 20 and the molding unit 30 are shown separately, but they can also be collectively referred to as the molding unit.

[0008] The material supply tank 21 is a container for holding powder material P, which is the material used to create three-dimensional objects. The bottom surface 211 of the material supply tank 21 moves along the vertical direction (Z direction) by a drive mechanism 212, which is composed of, for example, a piston. When the bottom surface 211 of the material supply tank 21 moves toward the Z-direction + side (upwards), the powder material P inside the material supply tank 21 is pushed out to the outside in proportion to the amount the bottom surface 211 rises, and this pushed-out powder material P is transferred to the molding tank 31, which will be described later, by a recoater 22, which will be described later.

[0009] The material supply tank 21 is equipped with a heater 213 for heating the powder material P contained inside. The heater 213 is controlled by a computing device 50 (described later) to heat the powder material P to a desired temperature. The heater 213 uses a conventional heating method. A temperature control element such as a Peltier element may also be used for the heater 213. By heating the powder material P in the material supply tank 21, the heater 213 raises the temperature of the powder material P before it is transferred to the molding tank 31 and heated by laser light irradiation (described later). This reduces the amount of heat required for the temperature of the powder material P to rise to a desired temperature (e.g., melting point) when heated by laser light irradiation. In addition, the heater 213 reduces the moisture absorption and fluidity of the powder material P by heating it, which has high moisture absorption and low fluidity. This makes it easier for the powder material P to be transferred to the molding tank 31, resulting in uniform flatness, layer thickness, and density of the material layer formed, as will be described in detail later. As a result, as will be described in detail later, when the material layer is irradiated with laser light, the temperature rise inside the material layer due to the laser light irradiation becomes uniform. The material supply tank 21 is not limited to one that pushes powder material P to the outside from the bottom in the Z direction by a drive mechanism 212. The powder material P contained in the material supply tank 21 is supplied to a dispenser located below the material supply tank 21 (on the Z-side), and the powder material P supplied to the dispenser falls onto the base plate 311 of the molding tank 31 from a discharge section located at the bottom of the dispenser (on the Z-side). The fallen powder material P may then be spread to a uniform thickness by the movement of a blade 221 of a recoater 22, which will be described later.

[0010] As the powder material P, for example, metal powder, resin powder, or powder in which metal particles are coated with a resin binder can be used. The metal powder may be a powder mainly composed of iron-based powder, or a powder that further contains at least one of the following: nickel powder, nickel-based synthetic powder, copper powder, copper-based alloy powder, and graphite-based powder. For example, a powder in which the amount of iron-based powder with an average particle size of about 20 μm is 60 to 90% by weight, the amount of either or both nickel powder and nickel-based alloy powder is 5 to 35% by weight, the amount of either or both copper powder and copper-based alloy powder is 5 to 15% by weight, and the amount of graphite powder is 0.2 to 0.8% by weight can be used. As the resin powder, for example, powders of polyamide, polypropylene, ABS, etc. with an average particle size of about 30 μm to 100 μm can be used. As the powder in which metal particles are coated with a resin binder, for example, a powder in which the surface of metal particles is coated with an additive such as phenolic resin or nylon may be used. In addition, ceramic powder may be used as the powder material P. The ceramic powder may be an oxide such as alumina or zirconia, or a nitride powder such as silicon nitride. The powder material P may also be a material other than those mentioned above. For example, the powder material P may be an existing metal powder, an existing resin powder, or an existing ceramic powder, or it may be a powder material combining at least two materials: an existing metal, an existing resin, and an existing ceramic. The following explanation will use the case where metal powder is used as the powder material P as an example.

[0011] The recoater 22 includes a blade 221 as a material layer forming member, a drive mechanism (not shown), and a blade mounting section (not shown). The blade 221 is, for example, a plate-shaped member extending along the Y direction. The blade 221 is attached to the blade mounting section in a way that allows it to be interchanged between multiple types with different materials and shapes. The drive mechanism includes, for example, a motor or a guide rail extending along the X direction, and moves the blade mounting section along the X direction, thereby moving the blade 221 along the X direction between position A (the X-side end of the material supply tank 21) and position B (the X-side end of the molding tank 31) in Figure 1. By moving the blade 221 in this way, the powder material P contained in the material supply tank 21 (more specifically, the powder material P pushed out of the material supply tank 21 according to the amount of rise of the bottom surface 211 of the material supply tank 21 to the Z-side (upward)) is transferred to the molding tank 31 of the molding section 30, which will be described later. At this time, the blade 221 moves while applying pressure to press the powder material P downwards (towards the Z-direction). This movement of the blade 221 causes the powder material P to be spread in the molding tank 31 to a constant thickness Δd, forming a layer of powder material called a powder bed (hereinafter referred to as a material layer) with a flat surface (the Z-direction + side). In other words, the blade 221 functions as a material layer forming member. The blade 221 can also apply pressure to the powder material P by a pressing mechanism (not shown) consisting of a cylinder or the like.

[0012] When the blade 221 transfers the powder material P to the top of the solidified layer formed as described later, after a predetermined time has elapsed since the solidified layer was formed by irradiating the previously formed material layer with laser light, the blade 221 moves again from position A along the X direction to transfer the powder material P to the top of the solidified layer. In this specification, this predetermined time is referred to as the waiting time of the blade 221. The above-mentioned constant thickness Δd is the thickness from the surface of the base plate 311 to the surface of the material layer (the Z-direction + side surface) when the powder material P is transferred onto the base plate 311 described later, and the thickness from the top surface of the solidified layer (the Z-direction + side surface) to the surface of the material layer formed on top of that solidified layer (the Z-direction + side surface) when the powder material P is transferred to the top of the solidified layer formed as described later. The movement speed of the blade 221, the pressure applied to the powder material by the blade 221, and the waiting time of the blade 221 are all controllable by the computing device 50. The formation of the material layer will be described in detail later. In this embodiment, a plate-shaped blade 221 is used as an example of a material layer forming member, but the material layer forming member can be a roller or any other member that can be used to form a material layer. For example, when a roller is used as a material layer forming member, the roller is mounted so that its rotation axis is aligned with the Y-axis direction, and when it moves along the X-direction by the drive mechanism, it moves while rotating. As a result, the roller applies pressure to the powder material P and spreads the powder material P into the molding tank 31 to a constant thickness Δd.

[0013] The molding tank 31 of the molding unit 30 is a container for molding operations to create a three-dimensional object by repeatedly forming a material layer and then forming a solidified layer by solidifying the formed material layer, thereby stacking multiple solidified layers along the Z direction. In this embodiment, as will be described later, the solidified layer is a layer formed by heating the powder material P that forms the material layer by irradiation with laser light, causing the powder material P to melt and solidify. The base plate 311, which is the bottom surface of the molding tank 31, is a support member that supports the formed material layer and the solidified layer from the Z-side. The base plate 311 moves along the vertical direction (Z direction) by a drive mechanism 312, such as a motor, included in the molding tank 31. As will be described in detail later, when a material layer formed from the powder material P supplied onto the base plate 311 is heated by irradiation with laser light to form a solidified layer, the base plate 311 moves downward (Z-side), and then a new material layer is formed on the upper surface (Z+ side) of the solidified layer. This new material layer solidifies to form a new solidified layer. The base plate 311 is attached to the build tank 31 in a way that allows it to be interchanged between multiple types of plates with different materials and thicknesses in the Z direction. In other words, the base plate 311 is attached to the build tank 31 in a way that allows it to be interchanged between multiple types of plates with different rigidities.

[0014] The base plate 311 is provided with a heater 313 for heating the base plate 311. The heater 313 is controlled by a computing device 50 (described later) to heat (preheat) the material layer and solidification layer supported by the base plate 311 to a desired temperature. The heater 313 uses a heater of an existing heating method. Alternatively, a temperature control element such as a Peltier element may be used as the heater 313. This heater 313 heats (preheats) the material layer and solidification layer inside the molding tank 31. The heater 313 preheats the powder material P that constitutes the material layer to a higher temperature before it is heated by laser irradiation. This reduces the amount of heat required for the temperature of the powder material P heated by laser irradiation to rise to a desired temperature (e.g., melting point). The heater 313 also heats the molded solidification layer. This suppresses the generation of residual stress during the cooling of the solidification layer and alleviates residual stress that has already occurred in the solidification layer.

[0015] The molding optical unit 35 of the molding unit 30 includes an acquisition unit 310, an illumination unit 32, a scanning unit 33, and a focus lens 323. The acquisition unit 310 includes an imaging device 41 (details to be described later), a bifurcated optical system 42, a chromatic aberration correction optical system 43, a half mirror 301, and a field diaphragm 302. The acquisition unit 310 acquires information from at least a portion of a predetermined region including a molten area where the powder material P is melted (a molten area where the powder material P is melted, an unmelted powder material P (material layer) that has not yet melted, a region that has solidified after melting, etc.) (details to be described later). The half mirror 301 does not have to be included in the acquisition unit 310, depending on the arrangement of each component of the molding optical unit 35 (details to be described later).

[0016] Here, since the acquisition unit 310 is integrally configured with the irradiation unit 32 and the scanning unit 33, for the sake of explanation, it will be described as part of the molding optics unit 35 (i.e., part of the molding unit 30). However, since the acquisition unit 310 has a different function from the other components of the molding unit 30 (i.e., the molding tank 31, irradiation unit 32, focus lens 323, and scanning unit 33) (a function to acquire information on at least a part of a predetermined area including the molten part where the powder material P is melted, as will be described later), it can also be described as a separate component from the molding unit 30. In this case, the molding unit 30 will have a molding optics unit 35 having an irradiation unit 32, a scanning unit 33, and a focus lens 323, and a molding tank 31. Also in this case, since the half mirror 301 is also part of the molding optics unit 35, it can also be described as a component of the molding optics unit 35 rather than the acquisition unit 310.

[0017] The irradiation unit 32 includes, for example, a laser oscillator 321 that emits laser light as irradiation light for heating a material layer, and a collimator lens 322 that collimates the laser light emitted from the laser oscillator 321 into parallel light (see Figure 2). As the laser oscillator 321, for example, a carbon dioxide laser, an Nd:YAG laser, or a fiber laser can be used. The laser oscillator 321 comprises, for example, an amplifier filled with a laser medium, such as a resonator mirror, and an excitation light source. Light emitted from the laser medium, excited by the light from the excitation light source, oscillates through repeated reflections within the amplifier and is emitted as laser light from the laser oscillator. The laser oscillator 321 can emit laser light in various modes (oscillation forms), including CW (continuous wave) oscillation, which continuously lights the excitation light source; normal pulse oscillation, which pulses the excitation light source and controls the output waveform of the laser light by electrically controlling the lighting time width and current value of the excitation light source; and Q-switched pulse oscillation, which emits laser light with a narrow pulse width and high peak output in a short time. The laser oscillator 321 emits laser light with a wavelength of 1070 nm, for example. The laser oscillator 321 may emit light of other wavelengths, such as infrared light greater than 800 nm, visible light in the range of 400 nm to 800 nm, or ultraviolet light shorter than 400 nm. The specific configuration of the irradiation unit 32 will be explained later. Furthermore, the irradiation unit 32, under control from the computing device 50, switches the intensity distribution of the laser light from the laser oscillator 321 between a Gaussian distribution and a top-hat distribution, etc., using a known shape-variable mirror or the like, and emits it. Furthermore, the irradiation unit 32 may irradiate the material layer with existing light-emitting diodes (LEDs), electron beams, proton beams, neutron beams, or other existing particle beams instead of laser light to heat the powder material P. In this embodiment, the irradiation unit 32 is one that can emit energy beams including existing laser light, existing light-emitting diodes, and existing particle beams.

[0018] The scanning unit 33 is composed of a galvanometer mirror and scans the laser light emitted from the irradiation unit 32 across the material layer along at least one of the X and Y directions. The specific configuration of the scanning unit 33 will be described later.

[0019] The imaging device 41 images the molten portion of the material layer irradiated and melted by the laser light from the irradiation unit 32 and a predetermined area near it, and generates image data of the predetermined area including the molten portion of the material layer and its vicinity. The generated image data is the signal intensity of each pixel obtained by photoelectric conversion of the light from the predetermined area including the molten portion of the material layer and its vicinity by the image sensor 411, which will be described later. The generated image data is output to the processing unit 50, which will be described later. The specific configuration of the imaging device 41 will be explained later. Furthermore, as mentioned above, the molding optics unit 35 partially shares a configuration for irradiating the material layer with laser light and a configuration for capturing an image of the material layer, and therefore can also be called an imaging optical system.

[0020] The housing 10 houses a material supply tank 21, a recoater 22, and a molding tank 31 in which the solidified layer is contained. Note that some parts of the drive mechanism 212 for moving the bottom surface 211 of the material supply tank 21 and some parts of the drive mechanism 312 for moving the base plate 311 of the molding tank 31 do not necessarily need to be housed inside the housing 10. The housing 10 has an air intake port 11 and an exhaust port 12. A tank 13 filled with an inert gas, such as argon or nitrogen, is connected to the air intake port 11 via an intake device 131 such as a valve. An exhaust device 14, such as a vacuum pump, is connected to the exhaust port 12. The exhaust device 14 and the air intake device 131, controlled by the computing device 50, exhaust the inside of the housing 10 to achieve a set pressure. The air intake device 131 also lowers the oxygen concentration inside the housing 10 by introducing the inert gas from the tank 13 into the housing 10. The oxygen concentration inside the housing 10 is reduced, preventing oxidation of the powder material P. The flow rate and velocity of the inert gas introduced into the housing 10 are controlled by the opening of the valve of the intake device 131 and the exhaust volume of the exhaust device 14. The housing 10 is equipped with a heater 15 for heating the inside, which is controlled by a calculation device 50 (described later) to heat the inside of the housing 10 to a desired temperature. The heater 15 uses an existing heating method. Alternatively, a temperature control element such as a Peltier element may be used as the heater 15. This heater 15 heats the material layer and solidification layer in the molding tank 31 by heating the inside of the housing 10. The heater 15 preheats the powder material P before it is heated by laser light irradiation. As a result, the temperature of the powder material P irradiated with laser light rises to the desired temperature (e.g., melting point), reducing the amount of heat required.

[0021] As described above, the atmosphere inside the housing 10, including the oxygen concentration, flow rate and velocity of the inert gas, type of inert gas, pressure inside the housing 10, and temperature inside the housing 10, is controlled. In addition, in order to transmit the laser light from the irradiation unit 32, at least a portion of the upper surface (Z-direction + side) of the housing 10 is formed of a light-transmitting material such as glass. This portion is, for example, the region that intersects with the optical path of the laser light traveling from the scanning unit 33 onto the material layer.

[0022] Here, we will explain an example of the specific configuration and arrangement of the 35 molding optics unit with reference to Figure 2. As shown in Figure 2, the laser light emitted from the laser oscillator 321 of the irradiation unit 32 toward the Z-direction is reflected toward the X-direction +direction by the half mirror 301, passes through the focus lens 323, and enters the scanning unit 33. Note that the direction of emission of the laser light from the irradiation unit 32 is not limited to the Z-direction -direction, and the direction in which the half mirror 301 reflects the laser light is not limited to the X-direction +direction. Based on the relationship between the position where the irradiation unit 32 is located and the positions where the material layer and / or other components of the molding optics unit 35 are located, the direction of emission of the laser light and the reflection direction of the half mirror 301 are determined to be in a suitably preferred direction.

[0023] The focus lens 323 has a concave lens 323a and a convex lens 323b. In order to adjust the focal position (focal length) of the laser beam reflected by the galvanometer mirrors 331 and 332, which will be described later, the concave lens 323a is configured to be movable along the X direction by a drive mechanism (not shown) controlled by the computing unit 50. Therefore, the beam diameter (spot size) of the laser beam on the material layer can be adjusted according to the position of the concave lens 323a in the X direction. In this case, the distance the laser beam travels to reach the surface of the material layer changes due to the driving of the galvanometer mirrors 331 and 332 (i.e., the change in the angle of the galvanometer mirrors 331 and 332), which will be described later. Therefore, the focus lens 323 can adjust the focal position of the laser beam in accordance with the driving of the galvanometer mirrors 331 and 332 so that the focal point of the laser beam reflected by the galvanometer mirrors 331 and 332 aligns with the surface of the material layer.

[0024] Furthermore, the focal position of the laser beam does not necessarily have to be adjusted so that the focal point of the laser beam aligns with the surface of the material layer when the galvanometer mirrors 331 and 332 are driven. For example, the position of the concave lens 323a may be controlled by a drive mechanism (not shown) controlled by the computing device 50 in accordance with the driving of the galvanometer mirrors 331 and 332 (change in the angle of the galvanometer mirrors 331 and 332) in order to change the beam diameter (spot size) of the laser beam for each laser beam irradiation position on the material layer. Note that the concave lens 323a does not necessarily have to be configured to be movable, the convex lens 323b may be configured to be movable in the X direction by a drive mechanism (not shown), or both the concave lens 323a and the convex lens 323b may be configured to be movable in the X direction by a drive mechanism (not shown). Also, the focus lens 323 does not have to be a so-called Galilean type including a concave lens 323a and a convex lens 323b, and other existing optical systems can be used. Furthermore, the focus lens 323 is not limited to configurations in which the concave lens 323a and convex lens 323b are movable in the X direction. Based on the relationship between the position where the focus lens 323 is positioned and the positions where the other components of the molding optics unit 35 are positioned, the direction of movement of the concave lens 323a and convex lens 323b is determined to be in a suitably preferred direction.

[0025] The scanning unit 33 includes galvanometer mirrors 331 and 332. Galvanometer mirror 331 is positioned at a predetermined angle of inclination with respect to the Z-axis. The inclination angle of galvanometer mirror 331 with respect to the Z-axis is changed by control from the computing unit 50. Galvanometer mirror 331 reflects laser light traveling from the focus lens 323 toward the X-direction + side toward galvanometer mirror 332, which is positioned toward the Z-direction + side of galvanometer mirror 331.

[0026] The galvanometer mirror 332 is positioned at a predetermined angle of inclination with respect to the XY plane. The inclination angle of the galvanometer mirror 332 with respect to the XY plane is changed by control from the computing unit 50. The laser light reflected by the galvanometer mirror 331 is reflected by the galvanometer mirror 332 and guided to the surface of the material layer. By changing the inclination angle of the galvanometer mirror 331 with respect to the Z axis and the inclination angle of the galvanometer mirror 332 with respect to the XY plane, the position on the material layer irradiated by the laser light moves along at least one of the X and Y axes. This makes it possible to move, or scan, the position on the material layer irradiated by the laser light on the XY plane. The arrangement of the galvanometer mirrors 331 and 332, and the direction of reflection of the laser light by the galvanometer mirror 331, are not limited to the arrangement and reflection direction described above. Based on the relationship between the position where the scanning unit 33 is located and the positions where the other components of the molding optics unit 35 are located, the arrangement of the galvanometer mirrors 331 and 332, and the direction of reflection of the laser light by the galvanometer mirror 331, can be determined to be an appropriate and desirable arrangement and reflection direction.

[0027] As the scanning angle amount set by the galvanometer mirrors 331 and 332 increases, the scanning distance of the laser beam increases. The scanning distance is the distance the irradiation position moves when the position on the material layer irradiated by the laser beam (irradiation position) moves on the XY plane. Also, as the speed at which the tilt angle of the galvanometer mirrors 331 and 332 is changed increases, the scanning speed of the laser beam increases. The scanning speed is the speed at which the irradiation position on the material layer moves on the XY plane. In other words, the computing unit 50 controls the scanning distance and scanning speed of the laser beam by controlling the scanning angle amount and the speed at which the galvanometer mirrors 331 and 332 are changed. The irradiation position of the laser beam on the surface of the material layer is determined by the tilt angle of the galvanometer mirrors 331 and 332. When imaging is performed by the imaging device 41 described later, the generated image data is stored in the storage unit 58, associated with irradiation position information and time information. Irradiation position information is information indicating the irradiation position of the laser beam. As described above, the irradiation position of the laser beam moves according to the tilt angle of the galvanometer mirrors 331 and 332, so the irradiation position of the laser beam on the material layer is calculated based on the tilt angle of the galvanometer mirrors 331 and 332 detected by an encoder or the like. The irradiation position information associated with the image data may also be the tilt angle of the galvanometer mirrors 331 and 332. Time information is time information indicating the timing when imaging was performed by the imaging device 41, with reference to the start of laser beam irradiation.

[0028] It should be noted that the scanning unit 33 is not limited to being composed of the galvanometer mirrors 331 and 332 described above. For example, the scanning unit 33 may be composed of a drive mechanism that moves the base plate 311 of the molding tank 31 along at least one of the X and Y directions. In this case, the drive mechanism is composed of a motor, a guide rail extending in the X direction, a guide rail extending in the Y direction, etc., and moves the base plate 311 on the XY plane. This changes the relative positional relationship between the laser beam irradiation position and the material layer on the XY plane, and the laser beam is scanned on the material layer. In this case, the laser beam may be scanned by moving the irradiation position of the laser beam on the XY plane by the galvanometer mirrors 331 and 332 and by moving the material layer on the XY plane due to the movement of the base plate 311. Alternatively, the tilt angles of the galvanometer mirrors 331 and 332 may be fixed, and the laser beam may be scanned by moving only the material layer on the XY plane due to the movement of the base plate 311. The configuration for changing the relative positional relationship between the laser beam and the base plate 311 (i.e., the material layer) on the XY plane is not limited to the configuration described above, and other existing configurations can also be applied.

[0029] Light (hereinafter referred to as thermal radiation light for convenience of explanation) from at least a portion of a predetermined region on the material layer that includes a molten region where the powder material P is melted (the molten region where the powder material P is melted, the unmelted powder material P (material layer) that has not yet melted, the region that has solidified after melting, etc.) travels in the opposite direction along a coaxial optical path with the laser light. That is, the thermal radiation light travels from the surface of the material layer toward the Z-direction + side, is reflected by the galvanometer mirror 332 toward the galvanometer mirror 331, and is reflected by the galvanometer mirror 331 toward the X-direction - side. The light from the predetermined region traveling toward the X-direction - side enters the focus lens 323, passes through the convex lens 323b and the concave lens 323a, and becomes a parallel beam of light. The thermal radiation light that has passed through the focus lens 323 passes through the half mirror 301, travels toward the X-direction - side, and enters the chromatic aberration correction optical system 43. Note that the optical element that reflects the laser light and transmits the thermal radiation light does not have to be a half mirror. For example, existing optical components such as dichroic mirrors may also be used.

[0030] The chromatic aberration correction optical system 43 corrects axial chromatic aberration, lateral chromatic aberration, etc., occurring in the thermal radiation light as it passes through the focusing lens 323. The chromatic aberration correction optical system 43 includes a first lens 431, a second lens 432, and a third lens 433, arranged in this order from the X-direction + side. The first lens 431 and the second lens 432 are cemented lenses, each combining a convex lens and a concave lens. The first lens 431 has a positive refractive index, the second lens 432 has a negative refractive index, and the third lens has a positive refractive index. The first lens 431 and the second lens 432 direct the incident thermal radiation light, which has passed through the half mirror 301, into the third lens 433 on the X-direction - side in the form of a parallel beam, and the third lens 433 focuses this parallel beam to form a primary image plane. The dispersion of the first lens 431, the second lens 432, and the third lens 433 is determined so that axial chromatic aberration and lateral chromatic aberration do not occur at this primary image plane. In this case, the dispersion of each lens is determined so that the chromatic aberration contained in the thermal radiation light transmitted through the first lens 431 and the second lens 432 is canceled out by the chromatic aberration caused by the focusing of the third lens 433. Furthermore, the arrangement of the first lens 431, second lens 432, and third lens 433 of the chromatic aberration correction optical system 43 is not limited to those arranged along the X direction. Based on the relationship between the position where the chromatic aberration correction optical system 43 is arranged and the positions where the other components of the molding optical unit 35 are arranged, the direction in which the first lens 431, second lens 432, and third lens 433 are arranged is determined to be an appropriate and desirable direction.

[0031] A field diaphragm 302 is positioned on the primary image plane. When thermal radiation passes through the aperture provided in the field diaphragm 302 toward the X-direction, the field of view of the image (image data) generated by the light beam incident on the imaging device 41 (described later) is limited. In this embodiment, the size of the aperture of the field diaphragm 302 is determined so that an image (image data) of a predetermined region including the laser beam irradiation position is generated. This suppresses the inclusion of images outside the predetermined region on the material layer in the image (image data). The thermal radiation that has passed through the field diaphragm 302 is incident on the bifurcated optical system 42 positioned toward the X-direction of the field diaphragm 302.

[0032] The bifurcated optical system 42 includes an objective lens 421, a light beam splitting unit 422, light beam deflection units 423 and 424, a light beam combining unit 425, an imaging lens 426, a first filter 427, and a second filter 428. The objective lens 421 is a collimating lens that collimates the thermal radiation light arriving from the field diaphragm 302 into parallel light. The light beam splitting unit 422 is composed of, for example, a dichroic mirror or a beam splitter, and transmits light beams of a specific wavelength from the thermal radiation light and reflects light beams of other wavelengths. In this embodiment, the light beam splitting unit 422 transmits light with wavelength λ1 from the incident thermal radiation light and guides it to the first filter 427 provided on the X-side, and reflects light with wavelength λ2 and guides it to the light beam deflection unit 423 provided on the Z-side. The light beam deflection section 423 is composed of, for example, a dichroic mirror, and reflects light with wavelength λ2, guiding it to the second filter 428 located on the X-side. In this embodiment, the explanation assumes that wavelength λ1 is, for example, 1250 [nm] and wavelength λ2 is, for example, 1600 [nm], but wavelengths λ1 and λ2 are not limited to the above values.

[0033] The first filter 427 is a bandpass filter that transmits light with a wavelength of λ1. Light with a wavelength of λ1 that has passed through the light beam splitting section 422 passes through the first filter 427 and is incident on the light beam deflection section 424 located on the X-side. The second filter 428 is a bandpass filter that transmits light with a wavelength of λ2. Light with a wavelength of λ2 that has been reflected by the light beam deflection section 423 passes through the second filter 428 and is incident on the light beam combining section 425. The light beam deflection section 424 is composed of, for example, a dichroic mirror, and the light beam reflection surface is positioned at a predetermined inclination angle with respect to the XY plane.

[0034] The light beam combining unit 425 is composed of, for example, a dichroic mirror, and the light beam reflection surface is positioned at a predetermined inclination angle with respect to the XY plane. Light with wavelength λ1 reflected by the light beam deflection unit 424 travels toward the Z+ side, passes through the light beam combining unit 425, is focused by the imaging lens 426, and enters the imaging device 41. Light with wavelength λ2 that enters the light beam combining unit 425 is reflected by the light beam combining unit 425, then travels toward the Z+ side, is focused by the imaging lens 426, and enters the imaging device 41. Here, the inclination angles of the reflection surface of the light beam deflection unit 424 and the inclination angles of the reflection surface of the light beam combining unit 425 are positioned at different angles from each other. Therefore, the light with wavelength λ1 from the beam deflection unit 424 and the light with wavelength λ2 from the beam combining unit 425 are incident on the imaging lens 426 at different angles, and are focused at different positions on the imaging surface of the image sensor 411 of the imaging device 41, which will be described later.

[0035] In this embodiment, the angle between the reflective surfaces of the light beam deflection unit 424 and the light beam combining unit 425 and the XY plane can be changed. Specifically, a drive mechanism (not shown) is provided to drive the reflective surfaces of the light beam deflection unit 424 and the light beam combining unit 425. The drive mechanism drives the reflective surfaces of the light beam deflection unit 424 and the light beam combining unit 425 according to control from the computing device 50, thereby changing the angle between the reflective surfaces and the XY plane. As a result, the incident position of light of wavelength λ1 and light of wavelength λ2 onto the image sensor 411 is changed in real time.

[0036] Furthermore, the angle between the reflective surface of the luminous beam splitting unit 422 and the reflective surface of the luminous beam deflection unit 423 and the XY plane may be adjustable. That is, a drive mechanism (not shown) is provided to drive the reflective surface of the luminous beam splitting unit 422 and the reflective surface of the luminous beam deflection unit 423, and the drive mechanism may drive the reflective surface of the luminous beam splitting unit 422 and the reflective surface of the luminous beam deflection unit 423 according to control from the computing device 50 to change the angle between the reflective surface and the XY plane. Moreover, the example is not limited to the case where the reflective surface of the luminous beam splitting unit 422 and the reflective surface of the luminous beam deflection unit 423 are driven by a drive mechanism, and the reflective surface of the luminous beam splitting unit 422 and the reflective surface of the luminous beam deflection unit 423 may be manually adjusted by the user. This manual adjustment is performed, for example, when the device is started up after delivery of the molding device 1 or during maintenance of the molding device 1. Furthermore, the arrangement of each component of the bifurcated optical system 42 and the reflection direction of the thermal radiation are not limited to the arrangement and reflection direction described above. Based on the relationship between the position where the bifurcated optical system 42 is located and the position where the other components of the molding optical unit 35 are located, the arrangement of each component of the bifurcated optical system 42 and the reflection direction of the thermal radiation are determined to be an appropriate and desirable arrangement and reflection direction.

[0037] The imaging device 41 includes an image sensor 411, which is composed of, for example, a CMOS or CCD, a readout circuit that reads out the image signal converted photoelectrically by the image sensor 411, and a control circuit that controls the driving of the image sensor 411. The thermal radiation light incident on the imaging device 41 is focused onto the imaging surface of the image sensor 411 by the imaging lens 426. The imaging device 41 converts the incident light beam photoelectrically, generates image data, and outputs it to the computing device 50. As described above, the tilt angles of the reflective surface of the light beam deflection unit 424 and the tilt angles of the reflective surface of the light beam combining unit 425 are arranged to be different from each other. Therefore, of the thermal radiation light from a predetermined region of the material layer, the light of wavelength λ1 reflected by the light beam deflection unit 424 and the light of wavelength λ2 reflected by the light beam combining unit 425 are incident on the imaging lens 426 at different angles and are focused at different positions on the imaging surface of the image sensor 411. In other words, the images of the two lights of different wavelengths from the thermal radiation light from a predetermined region of the material layer appear at different positions on the same image (on the same image data).

[0038] As described above, the angles that the reflective surfaces of the light beam deflection units 422 and 423 make with the XY plane, and the angles that the reflective surfaces of the light beam deflection unit 424 and light beam combining unit 425 make with the XY plane, can be changed. Therefore, by controlling the angles that the arithmetic unit 50 that the reflective surfaces of the light beam deflection unit 424 and light beam combining unit 425 make with the XY plane, it becomes possible to adjust the relative positional relationship between the position where the light with wavelength λ1 of the thermal radiation is focused on the image sensor 411 and the position where the light with wavelength λ2 is focused on the image sensor 411. Furthermore, as described above, if the angles between the reflective surface of the light beam splitting unit 422 and the reflective surface of the light beam deflection unit 423 can be changed, it is also possible to adjust the positions where the light with wavelength λ1 and the light with wavelength λ2 are focused on the image sensor 411 by changing the angles between the reflective surface of the light beam splitting unit 422 and the reflective surface of the light beam deflection unit 423.

[0039] As shown in Figure 2, the above-described configuration allows the optical system for irradiating with laser light and the optical system for imaging with the imaging device 41 to be arranged coaxially. This simplifies the optical system configuration and suppresses the increase in size of the device. Furthermore, the bifurcated optical system 42 allows light of two different wavelengths, λ1 and λ2, to be focused at different positions on the image sensor 411. That is, images of two different wavelengths of thermal radiation from a predetermined region of the powder material P that includes the molten portion (the molten portion of the powder material P, the unmolten powder material P (material layer), the region that has solidified after melting, etc.) appear at different positions on the same image (on the same image data). The detection unit 54 of the computing device 50, which will be described later, uses a known two-color method, which will be described later, to convert the ratio of the luminance information of the images at different positions on the same image (same image data) into the temperature of the predetermined region of the powder material P that includes the molten portion (the molten portion of the powder material P, the unmolten powder material P (material layer), the region that has solidified after melting, etc.). Here, luminance information refers to luminance values ​​or values ​​related to luminance. In a material layer irradiated with laser light, as will be described in detail later, there are regions where the powder material P is molten, regions where the powder material P is unmolten, and regions where it has solidified after melting, resulting in different phase states. Therefore, within a predetermined region of the material layer, the emissivity of light differs for each phase state. Furthermore, the emissivity of light also differs depending on the type of powder material P.

[0040] Furthermore, as will be described in detail later, fumes are generated from the region where the powder material P is melted when irradiated with laser light. Fumes are numerous fine particles that float in the air as the vapor of the powder material P turns into steam due to heating by laser light irradiation, and then cools in the air. Thermal radiation light containing two wavelengths is attenuated by scattering by fumes. However, in the two-color method, the temperature is converted based on the ratio (for example, the ratio of brightness values) of the brightness information of the image data generated based on light of wavelength λ1 and the brightness information of the image data generated based on light of wavelength λ2. Therefore, the emissivity of a predetermined region of the powder material P including the molten portion (the molten portion where the powder material P is melted, the unmolten powder material P (material layer) that has not yet melted, the region that has solidified after melting, etc.) and the thermal radiation light containing two wavelengths are not affected by scattering by fumes. For this reason, based on the image data generated by the imaging device 41, information on the state of the powder material P irradiated with laser light and information on the temperature of the material layer are obtained without being affected by fumes, etc.

[0041] Note that the configuration and arrangement of the 35 shaping optics unit are not limited to the example shown in Figure 2 above. For example, the acquisition unit 310 may have two imaging devices 41, with one imaging device capturing light of wavelength λ1 from the thermal radiation and the other imaging device capturing light of wavelength λ2 from the thermal radiation. The two imaging devices are arranged such that the imaging surface of the image sensor of one imaging device is parallel to the YZ plane, and the imaging surface of the image sensor of the other imaging device is parallel to the XY plane. The bifurcated optical system 42 has a light beam splitting unit 422, a first filter 427, and a second filter 428, as shown in Figure 2. Also, the field aperture 302 shown in Figure 2 is not provided. The third lens 433 of the chromatic aberration correction optical system 43 is positioned in front of each of the two imaging devices 41. That is, the first filter 427, the second filter 428, and the light beam splitting unit 422 of the bifurcated optical system 42 are positioned between the second lens 432 and the third lens 433 of the chromatic aberration correction optical system 43. The light beam that has passed through the first lens 431 and the second lens 432 of the chromatic aberration correction optical system 43 is transmitted by the light beam splitter 422 as light with wavelength λ1, passes through the first filter 427 and proceeds toward the X-side, where it is focused onto the image sensor of one imaging device by one of the third lenses 433. The light with wavelength λ2 reflected by the light beam splitter 422 proceeds toward the Z-side, passes through the second filter 428, and is focused onto the image sensor of the other imaging device by the other third lens 433. As a result, each imaging device is able to generate image data for different wavelengths.

[0042] Furthermore, the acquisition unit 310 may use a filter capable of switching the wavelength of transmitted light instead of the bifurcated optical system 42 shown in Figure 2. This filter is placed between the second lens 432 and the third lens 433 of the chromatic aberration correction optical system 43 and has a region that transmits light of wavelength λ1 (first region) and a region that transmits light of wavelength λ2 (second region). The first and second regions of the filter are alternately inserted into the optical path of the thermal radiation at predetermined time intervals. For example, a disc-shaped member (turret) is provided with a plurality of filters with different wavelength transmittances, the surface of the turret is arranged parallel to the YZ plane, and the turret is configured to be rotatable around its center by a drive mechanism (not shown). For example, if the turret is provided with a first filter and a second filter as a plurality of filters with different wavelength transmittances, when the turret rotates by the drive mechanism, the first filter and the second filter are alternately inserted into the optical path of the thermal radiation at time intervals corresponding to the rotation speed. Therefore, while the first filter is inserted in the optical path, light with wavelength λ1 of the thermal radiation is transmitted and focused onto the image sensor 411 of the imaging device 41 by the third lens 433, and while the second filter is inserted in the optical path, light with wavelength λ2 is transmitted and focused onto the image sensor 411 by the third lens 433. As a result, at time intervals corresponding to the rotation speed of the turret, the imaging device 41 generates image data based on light with wavelength λ1 and image data based on light with wavelength λ2. In this case, the field aperture 302 shown in Figure 2 is not provided. As a result, the imaging device 41 can generate image data for each different wavelength at time intervals corresponding to the rotation speed of the turret. Alternatively, filters for selecting wavelengths λ1 and λ2 may be placed on the image sensor 411 of the imaging device 41, depending on the arrangement of pixels constituting the image sensor 411. In this case, the bifurcated optical system 42 and field diaphragm 302 shown in Figure 2 are not provided. This makes it possible to generate image data of wavelengths λ1 and λ2.

[0043] Alternatively, as shown in Figure 3(a), the system may have a first focus lens 324 that adjusts the focal position of the laser beam on the material layer and a second focus lens 325 that adjusts the focal position of the radiant light from the material layer on the image sensor 411. The first focus lens 324 and the second focus lens 325 have concave lenses 324a, 325a and convex lenses 324b, 325b, similar to the concave lens 323a and convex lens 323b of the focus lens 323 shown in Figure 2. In the example shown in Figure 3(a), the laser light from the laser oscillator 321 travels in the Z-direction + direction, passes through the first focus lens 324, passes through the half mirror 301, and enters the scanning unit 33. The thermal radiation enters the half mirror 301 via the scanning unit 33, is reflected by the half mirror 301, and travels in the Z-direction + direction. The thermal radiation passes through the second focus lens 325, passes through the chromatic aberration correction optical system 43 which has the same configuration as shown in Figure 2, and enters the bifurcated optical system 42. Since the bifurcated optical system 42 also has the same configuration as shown in Figure 2, the thermal radiation becomes light split into two wavelengths, and each wavelength of light is focused at different positions on the image sensor 411 of the imaging device 41.

[0044] The laser oscillator 321 and the first focusing lens 324 may be arranged along the Z direction, and the second focusing lens 325, the chromatic aberration correction optical system 43, and the bifurcated optical system 42 may be arranged along the X direction. In other words, in the example shown in Figure 3(a), the acquisition unit 310 includes an imaging device 41, a bifurcated optical system 42, a chromatic aberration correction optical system 43, a second focus lens 325, and a half mirror 301. As a result, the acquisition unit 310 acquires information on a predetermined region of the powder material P that includes the molten portion (the molten portion of the powder material P, the unmolten powder material P (material layer) that has not yet melted, the region that has solidified after melting, etc.). Furthermore, since the acquisition unit 310 has a different function from the other components of the molding unit 30 (a function to acquire information on at least a portion of a predetermined area including the molten portion where the powder material P is melted), it can also be represented as a separate component from the molding unit 30 (molding optics unit 35). In this case, since the half mirror 301 is also part of the molding optics unit 35, it can also be represented as a component of the molding optics unit 35 rather than the acquisition unit 310.

[0045] Alternatively, as shown in Figure 3(b), an fθ lens 326 may be provided between the scanning unit 33 and the material layer instead of the focus lens 323. The fθ lens 326 is a lens that focuses light at an incident angle θ to a position with an image height of f × θ, where f is the focal length of the fθ lens 326. Therefore, when the laser beam is scanned by the scanning unit 33, the focal point of the laser beam, whose incident angle has changed due to the tilt angle of the galvanometer mirrors 331 and 332, is set to different positions on the same plane (i.e., on the material layer). In this case, the laser light emitted from the irradiation unit 32 travels towards the X-direction + side, passes through the half mirror 301, and is irradiated onto the material layer via the scanning unit 33 and the fθ lens 326. The thermal radiation light reaches the half mirror 301 via the fθ lens 326 and the scanning unit 33, is reflected towards the Z-direction + side by the half mirror 301, and enters the imaging device 41 via the first lens 431 and the bifurcated optical system 42. This makes it possible to generate image data for each different wavelength, as shown in Figure 2.

[0046] The laser oscillator 321 may be arranged along the Z direction, and the first lens 431 and the bifurcated optical system 42 may be arranged along the X direction. In other words, the acquisition unit 310 includes the imaging device 41 shown in Figure 3(b), a bifurcated optical system 42, a chromatic aberration correction optical system 43, and a half mirror 301. Through this, the acquisition unit 310 acquires information on a predetermined region of the powder material P that includes the molten portion (the molten portion of the powder material P, the unmolten powder material P (material layer), the region that has solidified after melting, etc.). Furthermore, since the acquisition unit 310 has a different function from the other components of the molding unit 30 (a function to acquire information on at least a portion of a predetermined area including the molten portion where the powder material P is melted), it can also be represented as a separate component from the molding unit 30 (molding optics unit 35). In this case, since the half mirror 301 is also part of the molding optics unit 35, it can also be represented as a component of the molding optics unit 35 rather than the acquisition unit 310.

[0047] The detection unit 54 does not necessarily have to use a two-color method. For example, temperature image data may be generated based on image data of any one wavelength of thermal radiation light from at least a portion of a predetermined area including the molten part where the powder material P is melted. In this case, the bifurcated optical system 42 of the acquisition unit 310 may be replaced with a configuration including an objective lens 421, a filter for selecting any one wavelength, and an imaging lens 426. In this case, the chromatic aberration correction optical system 43 of the acquisition unit 310 may be omitted. The detection unit 54 may generate temperature image data based not only on light of any one wavelength, but also on image data of any three or more wavelengths. Even in this case, the bifurcated optical system 42 of the acquisition unit 310 can be configured to increase the number of optical path branches.

[0048] The arithmetic unit 50 in Figure 1 is a processor that controls each part of the molding apparatus 1 by reading and executing a control program pre-stored in a storage unit 58, which is composed of a non-volatile storage medium (such as flash memory). The arithmetic unit 50 comprises a setting unit 59, a detection unit 54, an output unit 55, a calculation unit 56, and a determination unit 57. The arithmetic unit 50 may be composed of a CPU, an ASIC, a programmable MPU, etc.

[0049] The setting unit 59 sets various conditions (forming conditions) for the molding device 1 to form a three-dimensional object based on the status information output from the output unit 55, which will be described later. The status information will be explained later. The setting unit 59 comprises a material control unit 51, a molding control unit 52, and a housing control unit 53. The material control unit 51 controls the operation of the material layer forming unit 20 according to the material layer formation conditions, which are the conditions for forming a material layer. The material layer formation conditions include the moving speed of the blade 221, the pressure applied by the blade 221 to the powder material P, the waiting time of the blade 221, and the material of the blade 211. The material control unit 51 also controls the operation of the material layer forming unit 20 according to conditions related to the powder material P. Conditions related to the powder material P include the particle size / particle size distribution of the powder material P, the moisture absorption of the powder material P, and the type of powder material P, which will be described in detail later. In this case, the material control unit 51 controls the operation of the drive mechanism 212 that drives the bottom surface 211 of the material supply tank 21, and the heating temperature of the heater 213 that heats the powder material contained in the material supply tank 21. When change information is generated by the calculation unit 56, which will be described later, the material control unit 51 changes the operation of the material layer forming unit 20 according to the material layer formation conditions and conditions related to the powder material P based on the content of the change information.

[0050] The molding control unit 52 controls the operation of the molding unit 30. The molding control unit 52 controls the irradiation unit 32 based on the conditions of the laser light emitted to the powder material P to heat the powder material P. The laser light conditions include the output of the laser light, the wavelength of the laser light, the intensity distribution of the laser light, and the beam size (spot size) of the laser light, which will be described in detail later. The molding control unit 52 controls the scanning unit 33 based on the scanning conditions for scanning the laser light to heat the powder material P. The scanning conditions include the scanning speed of the laser light, the spacing between the irradiation positions of the laser light, and the scanning path of the laser light, which will be described in detail later. The molding control unit 52 controls the operation of the base plate 311 based on the support conditions related to the base plate 311 that supports the powder material P and the solidification layer. The support conditions include the temperature of the base plate 311, which will be described in detail later, and the molding control unit 52 controls the heating temperature of the heater 313 that heats the base plate 311 based on these support conditions. Furthermore, the molding control unit 52 controls the operation of the drive mechanism 312 that drives the base plate 311 of the molding tank 31. The molding control unit 52 modifies the design data of the solidification layer and the three-dimensional molded object according to the content of the change information. The design data includes slice model data and support part shape data, which will be described in detail later. When the change information is generated by the calculation unit 56, which will be described later, the molding control unit 52 modifies the operation of the molding unit 30 and the design data according to the content of the change information.

[0051] The housing control unit 53 controls the operation of the intake device 131 and exhaust device 14, and the operation of the heater 15, according to conditions related to the atmosphere inside the housing 10. Conditions related to the atmosphere inside the housing 10 include the flow rate and velocity of the inert gas introduced into the housing 10, and the temperature inside the housing 10, which will be described in detail later. When change information is generated by the calculation unit 56, which will be described later, the housing control unit 53 changes the operation of the intake device 131, exhaust device 14, and heater 15 according to the conditions related to the atmosphere inside the housing 10 based on the content of the change information. In addition to the control program described above, the memory unit 58 stores various types of information used when detecting the state of at least a part of a predetermined area including the molten portion by the detection unit 54 (described later), generating change information by the calculation unit 56, and performing determination processing by the determination unit 57.

[0052] The detection unit 54 determines the state of at least a portion of a predetermined area in the material layer based on the image data generated by the imaging device 41 described above. Here, the predetermined area includes, as will be described later, the molten area where the powder material P has melted due to laser irradiation, the unmelted powder material P (material layer) that has not yet melted, the area that has solidified after melting, the area where sputtering has occurred, and the area where fumes have been generated. In the following description, this predetermined area will be referred to as the detection target area.

[0053] The output unit 55 outputs state information based on the state of at least a part of the detection target area determined by the detection unit 54 to the setting unit 59 (i.e., at least one of the material control unit 51, the molding control unit 52, and the housing control unit 53) in order to set the molding conditions of the molding apparatus 1. The state information based on the state of at least a part of the detection target area determined by the detection unit 56, which will be described later, includes change information for changing the molding conditions for molding a three-dimensional object, and information about the state of at least a part of the detection target area itself detected by the detection unit 54. Hereinafter, for the sake of convenience in explanation, the expression "at least a part of the detection target area" will simply be referred to as the detection target area.

[0054] The calculation unit 56 generates modification information to change the molding conditions based on the state of the detection target area determined by the detection unit 54. Furthermore, if the determination unit 57, described later, determines that repair is necessary for the solidified layer that has been molded, the calculation unit 56 generates repair information to perform repairs on the solidified layer. The determination unit 57 determines whether or not to change the molding conditions based on the state of the detection target area determined by the detection unit 54. The determination unit 57 also determines whether or not to repair the molded solidified layer based on the state of the detection target area determined by the detection unit 54. Details of the processes performed by the detection unit 54, calculation unit 56, and determination unit 57 will be explained later.

[0055] Next, the operation of the molding apparatus 1 having the above configuration will be described. First, the housing control unit 53 controls the intake device 131, exhaust device 14, and heater 15 so that the inside of the housing 10 has a set atmosphere. The housing control unit 53 controls the valve opening of the intake device 131 and the exhaust volume of the exhaust device 14 so that the set pressure inside the housing 10 is obtained. In addition, the housing control unit 53 lowers the oxygen concentration inside the housing 10 by introducing an inert gas into the housing 10 by controlling the valve opening of the intake device 131. By lowering the oxygen concentration, oxidation of the powder material P when it is irradiated with laser light and melted, and the formation of an oxide film on the particle surface of the powder material P are suppressed. If an oxide film is formed on the particle surface of the powder material P, the specific heat changes according to the thickness of the oxide film, and as will be described later, when irradiated with laser light, it may affect the absorption and conduction of heat of the powder material P due to laser light irradiation. In this case, it may cause melting defects such as the powder material P not melting, shape defects or insufficient strength in the solidified layer that is formed, or failure to obtain a solidified layer with the desired metallic structure. By lowering the oxygen concentration inside the housing 10, oxidation of the powder material P, which causes melting defects such as those described above, is suppressed. The housing control unit 53 controls the heating output of the heater 15 to heat the inside of the housing 10 to the temperature set as the molding condition.

[0056] When an inert gas is introduced into the housing 10, the oxygen concentration becomes lower than a predetermined concentration, and the inside of the housing 10 is heated to a set temperature by the heater 15, the material control unit 51 controls the drive mechanism 212 to move (raise) the bottom surface 211 of the material supply tank 21 to the Z-direction + side. The molding control unit 52 controls the drive mechanism 312 to move (lower) the base plate 311 of the molding tank 31 to the Z-direction - side by the thickness Δd of the material layer to be formed. The material control unit 51 controls the drive mechanism of the recoater 22 to move the blade 221 along the X-direction from position A to position B. The blade 221, which started moving from position A, transfers the powder material P extruded from the material supply tank 21 by the rise of the bottom surface 211 onto the base plate 311 of the molding tank 31 on the X-direction + side. The powder material P transferred onto the base plate 311 is pressed downward (towards the Z-direction) by the lower end (towards the Z-direction) of the blade 221 moving towards the X-direction + side, thereby spreading the material on the base plate 311 with a uniform height (thickness in the Z-direction) from the surface of the base plate 311. This forms a material layer with a constant thickness (layer thickness) from the surface of the base plate 311. At this time, the movement speed of the blade 221 and the pressure applied by the blade 221 to the powder material P are controlled by the material control unit 51, so that the desired layer thickness, flatness of the material layer surface, density, etc., can be obtained by the user. Density is the ratio of the thickness of the material layer to the amount of powder material P in the formed material layer, and a lower density indicates a larger proportion of gaps within the material layer.

[0057] The irradiation unit 32 irradiates the formed material layer with laser light. The scanning unit 33 scans the laser light from the irradiation unit 32 on the surface of the material layer. The scanning path of the laser light (scanning path) is set based on slice model data, which is a collection of shape data obtained by slicing the design data of the three-dimensional object to be fabricated by the fabrication device 1, such as CAD data or STL data converted from CAD data, at predetermined intervals (for example, intervals of the layer thickness of the material layers) along the Z direction. This slice model data is the shape data of the solidified layer that determines the shape of the solidified layer in each layer.

[0058] The molding control unit 52 of the computing unit 50 determines a scanning path for scanning the laser beam by the scanning unit 33 so that the powder material P on the surface of the material layer is irradiated, according to the shape determined by the slice model data of the three-dimensional molded object corresponding to the position of the base plate 311 in the Z direction. Furthermore, in order to prevent deformation or damage to the three-dimensional object and the solidified layer during the printing process, the printing is carried out while forming support structures that support the solidified layer and the three-dimensional object. The shape data of the support structures, which represents information such as the shape and thickness of the support structures, is either the shape data of the three-dimensional object (i.e., the shape data of the support structures in the CAD data or STL data) or slice model data created based on the shape data of the three-dimensional object.

[0059] Furthermore, the build orientation data of a three-dimensional object is data that indicates the build orientation of the three-dimensional object (shape data of the three-dimensional object) used to set up slice model data. Build orientation refers to the orientation in which the three-dimensional object is built, for example, when building a prismatic three-dimensional object, whether the solidification layer is stacked along the axis of the prismatic, or whether the solidification layer is built from the side of the prismatic, along a direction intersecting the axis of the prismatic, and the solidification layer is stacked. Furthermore, when generating slice model data, it is preferable to generate the slice model data while considering shape changes due to thermal expansion, rather than using the design data as is. In particular, at the time the solidified layer is formed, the solidified layer is at a higher temperature than at room temperature due to laser irradiation. However, if there is a large difference between the temperature in the environment in which the three-dimensional object is used and the temperature when the solidified layer is formed, it is preferable to generate slice model data from data (shape data of the three-dimensional object) that has been modified as described above, taking into account the coefficient of linear expansion due to that temperature difference.

[0060] Furthermore, it is preferable to set tolerance information calculated based on CAD data for each individual slice model data. This tolerance information can be set for each slice model data in the manner described in, for example, Japanese Patent Publication No. 2006-59014. The design data for the shape of the three-dimensional object includes the shape data of the solidified layer, the printing orientation data, the shape data of the support parts that support the solidified layer or the three-dimensional object, or the shape data of the three-dimensional object itself. The printing control unit 52 scans the surface of the material layer with laser light from the irradiation unit 32 according to this design data. When the printing control unit 52 changes the design data of the three-dimensional object and modifies the slice model data based on the design data, the printing control unit 52 scans the surface of the material layer with laser light from the irradiation unit 32 according to the modified slice model data.

[0061] When laser light is irradiated onto powder material P, it is absorbed by the powder material P at an absorption rate determined by conditions such as the output and wavelength of the emitted laser light, the type of powder material P, the shape of the particles of powder material P, and the surface shape of the material layer. As the laser light is absorbed, the powder material P irradiated with the laser light is rapidly heated, its temperature rises, and heat is conducted to the surrounding powder material P. When the temperature rises due to heating reaches the melting point of the powder material P, the powder material P on the surface of the material layer melts and vaporizes, and the vapor pressure rises, causing the evaporated material to be ejected, forming a molten depression on the surface of the material layer. Laser light irradiated onto this depression is further absorbed into the molten area, and melting, vaporization, and ejection of evaporated material are repeated. As a result, the depression becomes a hole that increases in depth downward (towards the Z-direction) of the material layer, and the absorption rate of the laser light increases significantly due to multiple reflections of the laser light at the wall surface of the hole. This creates a deep hole (keyhole) with even greater downward depth. As described above, the multiple reflections of the laser light at the wall surface of the hole cause the cross-sectional shape of the keyhole in the XY plane to approach a circular shape. A keyhole is formed at the location where the laser beam is irradiated, causing the inside of the material layer to be directly heated. It is known that the shape of the keyhole becomes deeper as the energy transferred to the powder material P by the laser beam irradiation increases, and the opening becomes larger as the temperature of the powder material P increases. In the keyhole, as described above, the absorption rate of the laser beam reflected multiple times from the wall surface increases, causing evaporated material to be generated and ejected as a fume from the keyhole opening (top opening). Along with the ejection of the fume, a portion of the molten area around the keyhole (a portion of the molten powder material P) is scattered as particulate sputter.

[0062] When the laser beam is scanned by the scanning unit 33 with the keyhole formed, the keyhole is maintained by the balance of forces such as vapor pressure inside the keyhole, surface tension of the molten area, and gravity of the molten area. As a result of scanning, the powder material P located in the direction in which the laser beam is traveling (towards the X-direction + side when scanning towards the X-direction + side) melts. The molten liquid generated by the melting of the powder material P mixes with the molten liquid generated by the powder material P around the keyhole, forming a liquid phase molten pool around the keyhole.

[0063] Figure 4 schematically shows the state of the molten pool and its vicinity created by irradiating a material layer with laser light. Figure 4(a) is a schematic plan view showing the state of the molten pool and its vicinity on the material layer in the XY plane, and Figure 4(b) is a cross-sectional view in the ZX plane. In Figure 4, the keyhole KH formed as described above, the molten pool MP, the powder material P which has not yet begun to melt, the fume FU, the sputter SP, and the solidification region BE formed when the molten pool MP solidifies, as will be described later. Note that Figure 4 shows the case when the laser light is scanned from the + side to the - side in the X direction. Also, in Figure 4(a), the isotherms in the molten pool MP are shown as dashed lines. Inside the molten pool MP, convection occurs due to the difference in surface tension caused by the temperature difference between the surface and the interior of the molten pool MP, as shown by arrow C in Figure 4(b) as an example. When the heat generated by laser irradiation increases convection C, the amount of fume FU generated increases, and some of the molten powder material P around the keyhole KH is blown out of the molten pool MP and scattered around the keyhole KH and molten pool MP as sputter SP.

[0064] If the heat generated by laser irradiation becomes excessive, the convection C within the molten pool MP increases or becomes turbulent. When convection C increases, the molten pool MP is agitated more, which increases the amount of sputtered spatter scattered and the scattering velocity of sputtered spatter. Also, if convection C becomes turbulent and irregular within the molten pool MP, the scattering direction of sputtered spatter is not fixed in a constant direction relative to the keyhole KH (for example, behind the laser scanning direction), but is scattered in front of and to the sides of the laser scanning direction. Furthermore, the more excessive the heat generated by laser irradiation, the more fumes FU are generated, resulting in a higher concentration of fumes FU and a wider area over which fumes FU are generated from the keyhole KH and diffuse.

[0065] As the keyhole KH moves with the scanning of the laser beam, a new molten pool MP is formed around the keyhole KH on the side in the direction of travel (the X-direction - side in Figure 4). At the same time, the already formed (not yet solidified) molten pool MP is located relatively behind the keyhole KH (the X-direction + side in Figure 4). As a result, the overall shape of the molten pool MP becomes elliptical on the XY plane, as shown in Figure 4(a). As the laser beam is scanned and moves away from the irradiation position, the absorption of the laser beam's energy weakens, and areas cooled by factors such as the flow rate and velocity of the inert gas inside the housing 10 solidify, forming a solidified region BE. As the keyhole KH continues to move with the scanning of the laser beam, the powder material P solidifies in the region of the material layer irradiated by the laser beam, forming a continuous solidified region BE. By irradiating with laser beam so that the gap between the solidified region BE to be formed and the already formed solidified region BE (two solidified regions BE extending in the X direction in Figure 4(a)) is in contact, the formed solidified regions BE are welded together. The distance between two different solidification regions BE extending in the same direction is determined by the scanning interval (scanning pitch) when scanning the laser beam. The scanning interval (scanning pitch) is the distance between two adjacent laser beam irradiation positions in a direction intersecting the scanning direction of the laser beam (the X direction in Figure 4(a)) (the Y direction in Figure 4(a)). When multiple formed solidification regions BE are welded together, a layered solidified layer with a predetermined thickness is created along the Z direction.

[0066] During the formation of the solidified layer, the imaging device 41 images the surface of the material layer to generate image data. As shown in Figure 2, the thermal radiation incident on the imaging device 41 travels in the opposite direction along the same axis as the laser light emitted from the irradiation unit 32. Therefore, the center of the imaging field of view of the imaging device 41 (i.e., the center of the image captured by the imaging device 41) approximately coincides with the irradiation position of the laser light on the material layer. When the material layer is irradiated with laser light by the irradiation unit 32, the imaging device 41 images the detection target region, including the molten pool MP, in the XY plane, centered on the irradiation position of the laser light on the surface of the material layer (or the position of the keyhole KH if one is present), and generates image data. That is, the detection target region includes the powder material P of the material layer just before melting begins (unmelted powder material P), the molten pool MP, and the solidification region BE (in other words, a part of the solidified layer). Furthermore, if sputter SP or fume FU is generated from the keyhole KH, the sputter SP and fume FU are also included in the detection target region. As the scanning unit 33 scans with laser light, the detection target area captured by the imaging device 41 moves over the surface of the material layer. Imaging by the imaging device 41 is performed, for example, at predetermined time intervals or each time the laser beam is scanned by the scanning unit 33 over a predetermined distance on the XY plane.

[0067] Once the solidified layer is formed, the molding control unit 52 controls the drive mechanism 312 to move (lower) the base plate 311 of the molding tank 31 by the layer thickness Δd of the material layer to be formed in the Z-direction. The material control unit 51 controls the drive mechanism 212 to move the bottom surface 211 of the material supply tank 21 in the Z-direction + direction, and controls the drive mechanism of the recoater 22 to move the blade 221 along the X-direction from position A to position B. As a result, the powder material P is spread on top of the solidified layer (Z-direction + side) with a uniform height (thickness in the Z-direction from the top of the solidified layer). This forms a new material layer on top of the solidified layer with a constant layer thickness Δd from the top of the solidified layer.

[0068] The laser beam from the irradiation unit 32 is scanned on the XY plane by the scanning unit 33 over the new material layer. Irradiation with the laser beam melts the powder material P, forming a molten pool MP. As described above, this pool MP fuses with the adjacent solidified region BE in the X and Y directions, and the molten pool MP flows downwards (towards the Z direction), fusing with the already formed lower solidified layer (towards the Z direction). As a result, a new solidified layer is formed on top of the already formed solidified layer. The molding apparatus 1 repeatedly forms material layers and solidified layers to create a three-dimensional object in which multiple solidified layers are stacked along the Z direction.

[0069] As described above, when creating a three-dimensional object, if defects such as flaws, shape abnormalities, surface roughness, or abnormalities in the metallic structure occur in the solidified layer, it is difficult to repair these defects after the three-dimensional object has been created. In particular, it is difficult to repair defects inside the three-dimensional object. Furthermore, because there are many parameters for setting the conditions for creating a three-dimensional object, it is difficult and time-consuming to set the conditions for creating the object in advance to prevent defects from occurring. In the molding apparatus 1 of this embodiment, the detection unit 54, calculation unit 56, and determination unit 57 of the calculation unit 50 change various conditions for molding the three-dimensional object (hereinafter referred to as molding conditions) or generate information for repairing the solidified layer based on the state of the detection target area obtained at the start of molding or during molding of the three-dimensional object. Based on this information, the material control unit 51, molding control unit 52, and housing control unit 53 control the operation of each component of the molding apparatus 1 to prevent molding defects from occurring in the solidified layer during molding, or to repair molding defects at a timing when repair is possible, even if molding defects do occur.

[0070] The following describes the processes performed by the detection unit 54, the calculation unit 56, and the determination unit 57. First, I will explain the concept behind how the detection unit 54, calculation unit 56, and determination unit 57 perform the processing described later. In this embodiment, the following basic conditions are controlled to maintain a certain range in order to suppress the occurrence of molding defects in the solidified layer formed by irradiating the powder material P of the material layer with laser light from the irradiation unit 32, and to produce a three-dimensional object with suppressed molding defects. The basic conditions are the power density PD [J / mm²], which is the amount of heat that flows into the powder material P per unit area of ​​the material layer due to laser irradiation. 2 ] and the energy density ED [J / mm²], which is the amount of heat that flows into the powder material P per unit volume of the material layer due to laser irradiation. 2 Let us take the following as an example: the temperature distribution T(r) [°C] of the powder material P in the molten pool MP and its vicinity, which is being molten by laser irradiation. The power density PD, energy density ED, and temperature distribution T(r) are expressed by the following equations (1) to (3), respectively. PD = {η × (P L +P0)} / (d×v) …(1) ED = ρ × {η × (P L (+P0)} / (v×Δy×Δz) …(2) T(r) = {η × P} L / (2π×k×r)}×exp{(-v)×(x+r) / 2α}+T0 …(3)

[0071] In equations (1) to (3), the parameters are as follows: P LΔy is the laser output (hereinafter referred to as laser output) [W]. P0 represents the energy [W] added to the powder material P by an external heat source, i.e., the base plate 311, or by an external heater of the molding device 1. η is the energy absorption rate of the powder material P, and has different values ​​depending on the type of powder material P, for example. v is the scanning speed of the laser beam [mm / s]. d is the luminous beam size (spot size) of the laser beam on the surface of the material layer [mm]. Δy is the scanning path spacing (scanning pitch) [mm], i.e., the spacing of the laser beam irradiation positions in the direction intersecting the direction in which the laser beam is scanned. Δz is the layer thickness, i.e., the thickness of the formed material layer in the Z direction [mm]. ρ is the density of the material layer. k is the thermal conductivity of the powder material P [W / mm / K], r is the distance from the center of a sphere defined with respect to the laser beam irradiation position [mm], x is the distance on the XY plane along the scanning direction from the laser beam irradiation position [mm], and α is the thermal diffusivity of the powder material P [mm] 2 [ / s], T0 is the initial temperature [°C] of the powder material P.

[0072] The larger the power density PD shown in equation (1) above, that is, the greater the amount of heat flowing into the powder material P, the easier the powder material P is to melt. Equation (1) shows that in order to increase the power density PD and make the powder material P easier to melt, at least one of the parameters should be controlled based on the following policy. Regarding parameter η, for example, it is preferable to use a powder material P with a high laser light absorption rate. Parameter P L Regarding parameter P0, for example, it is advisable to increase the laser output or increase the amount of heat applied to the powder material P from the outside. Regarding parameter d, for example, it is advisable to increase the heat input efficiency of the amount of heat flowing into the powder material P by reducing the spot size of the laser beam and increasing the amount of heat per unit area on the material layer due to laser irradiation. Regarding parameter v, for example, it is advisable to increase the amount of heat flowing into the powder material P by lowering the scanning speed and increasing the time that the powder material P contained per unit area of ​​the material layer is irradiated with laser light.

[0073] Also, the smaller the value of the power density PD shown in formula (1), the less likely the powder material P is to melt. When the powder material P is over-melted, at least one of the above parameters may be controlled in a direction opposite to the above policy so that the value of the power density PD in formula (1) decreases. The opposite direction means that at least one of the policies exemplified below is carried out. Regarding the parameter η, for example, a powder material P with a low absorption rate is used. Regarding the parameters P L and P0, for example, the laser output is decreased or the amount of heat applied to the powder material P from the outside is decreased. Regarding the parameter d, for example, the spot size is increased. Regarding the parameter v, for example, the scanning speed is increased.

[0074] The larger the value of the energy density ED shown in formula (2), the easier it is for the powder material P to melt. Formula (2) represents that in order to increase the value of the energy density ED and make the powder material P easier to melt, at least one of the parameters may be controlled based on the following policy. Regarding the parameter η, similar to the case of formula (1) above, for example, a powder material P with a high absorption rate of laser light is used. Regarding the parameter P LRegarding parameter P0, for example, this can be done by increasing the laser output or increasing the amount of heat applied to the powder material P from an external heating device. Regarding parameter ρ, for example, this can be done by increasing the density of the material layer and reducing the gaps in the material layer. This makes it easier for the heat generated by the irradiation of laser light to conduct to the powder material P. Regarding parameter v, for example, this can be done by decreasing the scanning speed and increasing the time that the laser light is irradiated to the powder material P contained per unit area of ​​the material layer. This increases the amount of heat flowing into the powder material P. Regarding parameter Δy, for example, this can be done by narrowing the scanning pitch. This increases the influence of heat from the adjacent solidification region BE. Regarding parameter Δz, for example, this can be done by thinning the layer thickness. This increases the influence of heat from the solidified layer already formed in the lower layer (Z direction side), so the initial temperature of the powder material P is higher. Therefore, the amount of heat required for the powder material P irradiated with laser light to rise to the desired temperature (e.g., melting point) is reduced.

[0075] Furthermore, the smaller the value of the energy density ED shown in equation (2), the less likely the powder material P is to melt. If the powder material P is excessively melted, at least one of the above parameters should be controlled in the opposite manner to the above policy in order to reduce the value of the energy density ED in equation (2). The opposite policy means that at least one of the following examples is implemented. Regarding parameter η, for example, a powder material P with low absorption rate is used. Parameter P L Regarding P0, for example, this could be done by reducing the laser power or decreasing the amount of heat applied to the powder material P from the outside. Regarding the parameter ρ, for example, this could be done by decreasing the density. Regarding the parameter v, for example, this could be done by decreasing the scanning speed. Regarding the parameter Δy, for example, this could be done by widening the scanning pitch. Regarding the parameter Δz, for example, this could be done by increasing the layer thickness.

[0076] As power density PD and energy density ED increase, the powder material P melts more easily. However, if power density PD and energy density ED are increased too much, the convection C within the melting region MP is affected, leading to an increase in the generation of sputter SP and fumes FU. When sputter SP scattered from the molten pool MP by laser irradiation falls onto a material layer that has not yet been irradiated by laser light or onto an already formed solidification region BE and solidifies, it solidifies and remains as granular deposits on the surface of the material layer or the upper surface of the solidified layer. Because sputter SP is spherical, when a new material layer is formed on top of the solidified layer, it becomes difficult for the powder material P to penetrate between the area below the sputter SP solidified on the solidification region BE and the surface of the solidified layer, potentially creating voids. These voids, resulting from the inability of powder material P to penetrate, can cause melting defects such as cavities within the solidified layer when the next solidified layer is formed. Furthermore, if sputtered Furthermore, if fumes (FU) generated by laser irradiation accumulate near the laser irradiation site on the material layer, the energy of the laser beam directed towards the material layer is attenuated by the fumes. This reduces the heating effect of the powder material (P) by laser irradiation, potentially preventing the expected melting state from being achieved. Thus, poor melting due to sputtering (SP) adhesion and fume generation can lead to defects in the three-dimensional fabricated object, such as shape defects and insufficient strength due to the inability to obtain the desired metal structure (crystal structure) as a result of poor melting. As described above, sputtering (SP) and fumes (FU) are causes of poor fabrication in three-dimensional fabricated objects. Therefore, to suppress the generation of sputtering (SP) and fumes (FU), it is necessary to control the power density (PD) and energy density (ED) so that they do not increase excessively.

[0077] Furthermore, if the power density PD or energy density ED decreases too much, the powder material P will not be able to receive sufficient energy from the irradiated laser light, resulting in melting defects such as the powder material P not melting (unmelted) or not being able to obtain a molten pool MP of the desired size, leading to defects in the fabrication of the three-dimensional object. For this reason, it is necessary to control the power density PD and energy density ED so that they do not decrease too much. Thus, power density (PD) and energy density (ED) must be kept within a certain range, without becoming excessively large or small. This range is calculated from the results of various tests and simulations conducted by the user to ensure that the 3D printed object is of good quality. The range of power density (PD) and energy density (ED) that results in a good 3D printed object is referred to as the desired range.

[0078] The temperature distribution T(r) shown in equation (3) represents the temperature that is expected to be obtained at a position (x, y, z) at an arbitrary distance r from the laser beam irradiation position on or within the material layer, when the laser beam is irradiated onto the material layer under the currently set molding conditions. In other words, equation (3) is an equation that estimates the state of heat conduction due to laser beam irradiation within the material layer when the laser beam is irradiated under the currently set molding conditions. Therefore, equation (3) allows estimation of the progress of melting or solidification after melting of the powder material P on the surface (X and Y directions) and in the depth direction (Z direction) of the material layer. Equation (3) allows estimation of the state in which the temperature of the powder material P changes depending on the distance from the position where the laser beam was irradiated. Therefore, it is possible to grasp the range estimated to be the molten pool MP, which is a region with a temperature higher than a predetermined temperature (for example, an elliptical range on the XY plane). It is possible to grasp the temperature distribution of the range estimated to be the molten pool MP in three dimensions according to the distance from the laser beam irradiation position. Therefore, by setting the molding conditions so that the temperature distribution T(r) is kept within a certain range, the temperature changes within the molten pool MP are controlled. This makes it possible to maintain the desired crystal structure within the solidified layer after solidification, and to control the convection C in the molten pool MP.

[0079] Furthermore, the convection C in the molten pool MP caused by laser irradiation affects the shape of the molten pool MP (i.e., the shape of the solidified region BE after solidification and the depth of penetration during melting in the Z-direction). Therefore, by maintaining the temperature distribution T(r) within a certain range, the state of convection C in the molten pool MP, which is the thermal behavior caused by laser irradiation within the molten pool MP, is controlled. This suppresses the occurrence of poor penetration and reduces the occurrence of molding defects such as insufficient strength and reduced durability of the solidified layer. Also, as mentioned above, convection C affects the generation of sputter SP and fume FU, so by maintaining the temperature distribution T(r) within a certain range, the generation of sputter SP and fume FU is suppressed, and the occurrence of molding defects caused by sputter SP and fume FU is suppressed. This certain range is calculated from the results of various tests and simulations by the user so that the three-dimensional printed object is a good product. The certain range of temperature distribution T(r) that results in a good three-dimensional printed object is referred to as the desired range. Furthermore, it is sufficient that at least one of the basic conditions (1) to (3) satisfies the desired range.

[0080] Next, we will explain the processes performed by the detection unit 54, the calculation unit 56, and the determination unit 57 in order to change the molding conditions based on the above-mentioned equations (1) to (3). The detection unit 54 determines the state of the detection target area based on the image data from the imaging device 41. The state of the detection target area includes at least one of the following states: the state of the powder material P before heating by laser irradiation, the state of melting in the detection target area, the state of sputtering SP, and the state of fume FU generated by heating due to laser irradiation. As an example of the melting state in the detection target area, the detection unit 54 obtains information regarding the temperature of at least a portion of the molten pool MP and its vicinity (the semi-solidified region where the solution is about to become a solid phase after melting, and the solidified region BE). As the state of sputtering SP, the detection unit 54 determines at least one of the following: the scattering direction of sputtering SP, the amount of scattering, and the scattering velocity. As the state of fume FU, the detection unit 54 determines at least one of the following: the concentration and range of fume FU. Furthermore, determining the state of the detection target area can be rephrased as measuring the state of the detection target area, calculating the state of the detection target area, evaluating the state of the detection target area, or detecting the state of the detection target area, considering the state of the detection target area (specifically, the state of the powder material P, the melting state, the sputtering SP state, the fume FU state, etc., as mentioned above).

[0081] In this embodiment, the changes to the molding conditions based on the state of the detection target area determined by the detection unit 54 include real-time changes, changes during the molding of the next layer, and changes during the molding of the next molded object. In real-time changes, the molding conditions are changed when the solidification layer is molded by laser irradiation or during the molding process for the material layer used to determine the state of the detection target area. Therefore, in real-time changes, the molding conditions are changed for the unmelted powder material P in the material layer during the molding of the solidification layer. In changes during the molding of the next layer, the molding conditions are changed after the molding of the solidification layer, when the next material layer is formed or when the molding of the solidification layer is started from the next material layer. Therefore, in changes during the molding of the next layer, the molding conditions are changed for the new powder material P supplied onto the molded solidification layer or the new powder material P supplied onto the solidification layer. In changes during the molding of the next molded object, the molding conditions are changed when the molding of the three-dimensional object is completed by stacking solidification layers and the molding of the next three-dimensional object is started.

[0082] The following explanation will be divided into two parts: the process of determining the state of the detection target area by the detection unit 54, and the process of generating change information for changing the molding conditions by the calculation unit 56.

[0083] (1) Process to determine the state of the area to be detected The detection unit 54 uses image data generated by the imaging device 41 to determine the state of the target area on the material layer. As described above, the image data output from the imaging device 41 contains information on light of different wavelengths λ1 and λ2 from the thermal radiation light of the target area. The detection unit 54 determines information on the temperature of the molten pool MP and at least a portion of its vicinity based on the ratio of the luminance information of wavelength λ1 contained in the image data of the target area to the luminance information of wavelength λ2 contained in the image data. In this case, the detection unit 54 generates image data (hereinafter referred to as temperature image data) in which the luminance information of wavelengths λ1 and λ2 in the image data is converted to temperature, for example, using a known two-color method. Temperature image data is the signal intensity for each pixel corresponding to temperature. The detection unit 54 calculates the ratio of the luminance information of light of wavelength λ1 contained in the image data to the luminance information of light of wavelength λ2 (for example, the ratio of luminance values), compares it with reference luminance value ratio and temperature relationship data obtained based on gray bodies, black bodies, etc., and converts the ratio of luminance values ​​of wavelengths λ1 and λ2 at any position on the image data to temperature. This generates temperature image data representing the temperature at any position in the detection target area on the image data. From this temperature image data, the detection unit 54 can determine the temperature distribution of the detection target area, the maximum temperature, the minimum temperature, the average temperature, etc. The detection unit 54 generates temperature image data for each image data generated by the imaging device 41. Each time the detection unit 54 generates temperature image data, it stores and saves it in the storage unit 58.

[0084] Figure 5 schematically shows an example of a temperature image corresponding to the temperature image data generated by the detection unit 54 based on image data of the detection target area shown in Figure 4(a), and shows the case when the laser beam is scanned on the material layer from the + side to the - side in the X direction. In Figure 5, for illustrative purposes, the temperature difference in the molten pool MP of the temperature image is represented by isotherms shown by dashed lines, and the area affected by fumes FU is indicated by diagonal lines.

[0085] As described above, when the material layer is irradiated with laser light, the imaging device 41 images the detection target area of ​​the material layer, including the molten pool MP. Therefore, the generated temperature image data (temperature image) includes the molten pool MP, the solidified region BE where solidification has been completed, and the powder material P, with the keyhole KH as the center of the image. Since the laser light is scanned toward the X-direction-side, in the temperature image, the molten pool MP has a larger elliptical region toward the X-direction+ side than toward the X-direction-side relative to the keyhole KH. Also, if granular sputter SP is scattered by the irradiation of the laser light, the sputter SP also has heat and is therefore included in the temperature image data (temperature image). Also, if fumes FU, which are evaporated materials, are generated by the irradiation of the laser light, the fumes FU also have heat and are therefore included in the temperature image data (temperature image).

[0086] The detection unit 54 uses a temperature image, as illustrated in Figure 5, to determine the state of the target region, including the state of the powder material P before heating by laser irradiation, the state of melting in the target region, the state of sputtering SP, and the state of fume FU. The following explanation will be divided into the detection of the state of the target region, the detection of the state of the powder material P before heating by laser irradiation, the detection of the state of melting in the target region, the detection of the state of sputtering SP, and the detection of the state of fume FU.

[0087] <Detection of the state of powder material P before heating by irradiation with laser light> The detection unit 54 obtains information regarding the temperature of regions other than the molten pool MP and the solidification region BE from the temperature image data, as this represents the state of the powder material P before heating by laser irradiation. In this case, the detection unit 54 obtains regions that are lower than the first predetermined temperature. The first predetermined temperature is set, for example, based on the melting point of the powder material P. Note that the first predetermined temperature is not limited to the melting point, but may be the solidus temperature or the liquidus temperature, or any temperature within the range from the solidus temperature to the liquidus temperature. Here, when the detection unit 54 determines the temperature of the powder material P in the material layer before heating by laser irradiation, it can estimate the region in the scanning direction relative to the laser irradiation position as the region on the material layer for which the temperature of the powder material P should be determined. The detection unit 54 determines the region among these estimated regions that is lower than the first predetermined temperature as the temperature of the powder material P before heating by laser irradiation.

[0088] The detection unit 54 may determine the molten pool MP and solidification region BE from image data of the target area captured by an imaging device different from the imaging device 41, and then remove the molten pool MP and solidification region BE from the temperature image data based on the molten pool MP and solidification region BE obtained from the image data to determine the powder material P before heating by laser irradiation on the temperature image data. In this case, it is necessary to control the timing so that the imaging device 41 and the imaging device different from the imaging device 41 capture the target area in the same time.

[0089] Using temperature image data, the detection unit 54 determines information regarding the temperature of the powder material P before heating by laser irradiation, such as the temperature distribution of the powder material P before heating, the maximum temperature, the minimum temperature, and the average temperature. This allows the detection unit 54 to determine the initial temperature T0, which is a parameter of equation (3) above. Furthermore, the detection unit 54 may use known image processing methods to determine the state of the powder material P before heating, including foreign matter and sputtering SP contained in the powder material P, from the image data captured by the imaging device 41.

[0090] Furthermore, the detection unit 54 does not need to determine the state of the powder material P before heating by laser irradiation from the two-color method temperature image data. For example, the acquisition unit 310 may use an existing radiation thermometer instead of the imaging device 41, the bifurcated optical system 42, the chromatic aberration correction optical system 43, and the field aperture 302 to acquire temperature data based on infrared radiation from the powder material P before heating by laser irradiation. In this case, the detection unit 54 may determine the state of the powder material P before heating by laser irradiation based on the temperature data acquired by the acquisition unit 310 (radiation thermometer not shown).

[0091] Furthermore, the acquisition unit 310 does not have to be a radiation thermometer; an existing contact-type thermometer such as a thermocouple may be used. In this case, multiple thermocouples are installed at arbitrary positions in the molding tank 31 of the molding unit 30 or the material layer forming unit 20, and temperature data is acquired at each position using these multiple thermocouples. The detection unit 54 may then use data relating to the correlation between the temperature data acquired by the thermocouples and the temperature data of the powder material P before heating by laser irradiation to determine the state of the powder material P before heating by laser irradiation. Note that the data relating to the correlation between the temperature data acquired by the thermocouples and the temperature data of the powder material P before heating by laser irradiation is stored in the storage unit 58 beforehand.

[0092] <Detection of molten state> The detection unit 54 obtains information regarding the temperature of the molten pool MP and its vicinity (solidification region BE within the detection target area) from the temperature image data as the molten state. In this case, the detection unit 54 identifies the region with a high temperature of 1 or higher from the temperature image data as the region including the keyhole KH and the molten pool MP. Furthermore, when the detection unit 54 is determining the temperature of the solidification region BE after laser irradiation, it can estimate the region in the opposite direction to the scanning direction with respect to the laser irradiation position as the region where the temperature of the solidification region BE should be determined. The detection unit 54 determines the region with a temperature lower than the 1 predetermined temperature from this estimated region as the temperature of the solidification region BE after heating by laser irradiation. The detection unit 54 may also determine the temperature of a region (semi-solid region) where the liquid phase molten pool MP has started to solidify and become solid, by separating it from the keyhole KH and the molten pool MP within the region of the temperature image data that is above a first predetermined temperature, and then estimate the temperature of this region.

[0093] The detection unit 54 determines information related to the temperature of the molten pool MP and at least a portion of its vicinity, including the temperature distribution of the molten pool MP, the maximum temperature, minimum temperature, average temperature, the location of the keyhole KH, the opening diameter of the keyhole KH at the top surface (surface of the material layer) (e.g., the length of the minor axis), the size of the molten pool MP, the thermal conductivity, the temperature gradient on the surface of the molten pool MP, the solidification rate which is the change in temperature at the boundary of the molten pool MP on the surface, and the temperature history. Similarly, the detection unit 54 determines information related to temperature, including the temperature distribution of the solidified region BE and the semi-solidified region, the maximum temperature, minimum temperature, average temperature, size, thermal conductivity, temperature gradient, solidification rate, and temperature history.

[0094] The detection unit 54 determines the temperature distribution of the molten pool MP by, for example, determining the temperature at multiple locations in the region estimated as the molten pool MP in the temperature image data and setting isotherms for each predetermined temperature. The detection unit 54 determines the highest temperature as the maximum temperature and the lowest temperature as the minimum temperature in the region estimated as the molten pool MP in the temperature image data. The detection unit 54 determines the average temperature of the molten pool MP by determining the temperature at each of the multiple locations in the region estimated as the molten pool MP in the temperature image data and calculating the average of the determined temperatures. The detection unit 54 determines the center of the temperature image data as the position of the keyhole KH. The detection unit 54 determines the range that can be considered to have approximately the same temperature as the temperature at the center of the temperature image data as the opening of the keyhole KH on the uppermost surface, and determines the length of the minor axis of the determined opening as the opening diameter.

[0095] The detection unit 54 determines the size of the molten pool MP from the area of ​​the region on the temperature image that is above a first predetermined temperature. From the size of this molten pool MP, the detection unit 54 determines the thermal conductivity. In this case, the detection unit 54 converts the distance from the keyhole KH to the position of the first predetermined temperature in the temperature image data into a distance r on the material layer, inputs the value of the first predetermined temperature, the distance r, and the values ​​of each parameter determined by the currently set molding conditions into equation (3) above, and calculates the thermal conductivity by solving equation (3) for parameter k. The detection unit 54 determines the temperature gradient on the surface of the molten pool MP and the solidification rate, which is the change in temperature at the boundary of the molten pool MP on the surface, based on the degree of density of isotherms on the temperature image (temperature image data). Using multiple temperature image data generated by imaging at predetermined intervals, the detection unit 54 determines the temperature history of the molten pool MP and its vicinity. The temperature history is data representing the temperature change at a certain point in the material layer. An example of temperature history detection is described below.

[0096] As described above, the image data generated by the imaging device 41, the irradiation position information indicating the laser beam irradiation position (i.e., the position of the keyhole KH), and the time information are stored in association with each other. The detection unit 54 determines the temperature history based on the irradiation position information associated with the image data. The temperature history detection process by the detection unit 54 will be explained using the example of determining the temperature history at a position Q1 located a distance m in the X direction + side from position Q2 where the keyhole KH (i.e., the image center) is located in a certain temperature image (first temperature image). The detection unit 54 determines the temperature at position Q1 from the first temperature image data. Then, after a predetermined time (after the laser beam irradiation position has changed by a predetermined distance), the detection unit 54 determines the position of position Q1 on a second temperature image which is different from the first temperature image.

[0097] Specifically, the detection unit 54 determines the position of keyhole KH1, which is the center of the first temperature image, on the material layer, and the position of keyhole KH2, which is the center of the second temperature image, on the material layer, based on the laser beam irradiation position when the first image data was generated and the laser beam irradiation position when the second image data was generated. Assuming that the laser beam is scanned toward the X-direction - side, the position Q2 on the second temperature image (keyhole KH in the first temperature image) is obtained by shifting the center of the second temperature image toward the X-direction + side by the difference n between the positions of keyhole KH1 and KH2 on the material layer, converted into a distance on the temperature image. The detection unit 54 determines the position of position Q1 as the position located a distance m further toward the X-direction + side from position Q2 on the second temperature image, and determines the temperature at this position from the second temperature image data. The detection unit 54 can then determine the temperature history at position Q1 by similarly determining the temperature at position Q1 from multiple temperature image data.

[0098] The detection unit 54 obtains information regarding the temperature of the solidification region BE as the state near the molten pool MP from the temperature image data. In this case, the detection unit 54 obtains the temperature distribution and average temperature of the solidification region BE, etc. Alternatively, the detection unit 54 may obtain information regarding the temperature of the powder material P, which was obtained as the state of the powder material P before heating, as the state near the molten pool MP.

[0099] Furthermore, the detection unit 54 does not need to obtain information about the temperature of the molten pool MP and its vicinity (solidification region BE within the detection target area) (i.e., the state of moltenness) from the two-color temperature image data. For example, the acquisition unit 310 may use an existing radiation thermometer instead of the imaging device 41, the bifurcated optical system 42, the chromatic aberration correction optical system 43, and the field aperture 302 to acquire temperature data based on infrared radiation from the molten pool MP and its vicinity. In this case, the detection unit 54 may determine the state of moltenness based on the temperature data acquired by the acquisition unit 310 (radiation thermometer not shown).

[0100] Furthermore, the acquisition unit 310 does not have to be a radiation thermometer; an existing contact-type thermometer such as a thermocouple may be used. In this case, multiple thermocouples are installed at arbitrary positions in the molding tank 31 of the molding unit 30 or the material layer forming unit 20, and temperature data is acquired at each position using these multiple thermocouples. The detection unit 54 may then determine the melting state using data relating to the correlation between the temperature data acquired by the thermocouples and the temperature data of the molten pool MP or its vicinity (solidification area BE within the detection target area). Note that the data relating to the correlation between the temperature data acquired by the thermocouples and the temperature data of the molten pool MP or its vicinity (solidification area BE within the detection target area) is stored in the storage unit 58 beforehand.

[0101] <Detection of the state of sputtered sputtering sputtering> The detection unit 54 determines at least one of the following as the state of spatter SP: the amount of spatter SP scattered, the scattering direction, and the scattering velocity. As described above, since the state of spatter SP is related to the convection C inside the molten pool MP, the detection unit 54 can indirectly determine the state of the convection C inside the molten pool MP by determining the state of spatter SP.

[0102] Figure 6 shows a temperature image from Figure 5 with the fume FU and solidification region BE excluded, as it corresponds to the temperature image data used to determine the state of the sputtered SP for explanatory purposes. The detection unit 54 sets the region of interest used to determine the state of the sputtered SP within the temperature image data.

[0103] In this case, the detection unit 54 sets the region of interest as the region excluding the area occupied by the keyhole KH and the molten pool MP in the temperature image shown in Figure 6(a). The detection unit 54 can estimate the region including the keyhole KH and the molten pool MP (the region to be excluded) from equation (3) which represents the temperature distribution T(r) described above. Equation (3) which represents the temperature distribution T(r) represents the temperature of the powder material P at an arbitrary distance r from the laser beam irradiation position (i.e., the position of the keyhole KH), as described above, and uses the fabrication conditions for fabricating a three-dimensional object, such as the laser beam output, as parameters.

[0104] The detection unit 54 determines a high-temperature region of a first predetermined temperature or higher, including the position of the keyhole KH (i.e., the center of the temperature image), based on equation (3) which represents the temperature distribution T(r) and the set molding conditions, and determines the determined high-temperature region as the region to be excluded. As described above, the molten pool MP is elliptical in shape on the XY plane, so the region consisting of the keyhole KH and the molten pool MP is elliptical. The detection unit 54 inputs the value of the first predetermined temperature and the values ​​of each parameter determined by the currently set molding conditions into the temperature distribution T(r) of equation (3), and calculates the parameter r to calculate an elliptical region that is hotter than the first predetermined temperature. The detection unit 54 detects the region included in the calculated elliptical region as a high-temperature region on the temperature image data (temperature image), and determines this high-temperature region as the region to be excluded. Furthermore, the exclusion region is not limited to cases where an elliptical region including the keyhole KH and molten pool MP is detected; a region including the solidification region BE in addition to the elliptical high-temperature region may also be detected as an exclusion region.

[0105] Figure 6(b) schematically shows the exclusion region R1 (shown with diagonal lines in Figure 6(b)) obtained by the detection unit 54 from the temperature image shown in Figure 6(a), and the region of interest R2 set based on the obtained exclusion region R1. The region of interest R2 is the region where melting of the powder material P due to laser irradiation does not occur. Therefore, if a high-temperature region exists in the region of interest R2, the detection unit 54 identifies that high-temperature region as sputtered SP. The detection unit 54 determines the amount of sputtered SP by counting the number of high-temperature regions included in the region of interest R2.

[0106] The detection unit 54 can determine the scattering direction of the sputtered SP on the XY plane by determining the orientation from the center of the temperature image, i.e., the irradiation position of the laser beam, to each high-temperature region included in the region of interest R2. The detection unit 54 uses multiple temperature image data to determine the scattering velocity of sputter SP. Similar to how temperature history is determined, for example, the detection unit 54 extracts sputter SP that have fallen onto and solidified on the material layer or solidification region BE, i.e., sputter SP remaining in the same location on the material layer or solidification region BE, from two temperature image data with different time information, and excludes them from the scattering velocity detection target. Of the remaining sputter SPs to be detected (i.e., sputter SPs that have been displaced over time), the detection unit 54 identifies sputter SPs whose size and temperature in one temperature image data (temperature image) are considered to be the same as those in the other temperature image data (temperature image) as scattering sputter SPs (identical sputters). For the sputter SPs identified as identical sputters, the detection unit 54 determines the position in the upper space of the material layer (first position) from one temperature image data (temperature image) and the position in the upper space of the material layer (second position) from the other temperature image data (temperature image). The detection unit 54 calculates (detects) the scattering velocity of sputter SP (scattered identical sputter) from the first position, the second position, and the time information of the two temperature image data.

[0107] The detection unit 54 may determine the state of sputtered SPs without setting a region of interest R2 in the temperature image data (temperature image). In this case, the detection unit 54 generates average temperature image data by adding up multiple temperature image data generated from the image data output by the imaging device 41 and taking the average. The multiple temperature image data may be temperature image data generated from image data associated with different time information. Alternatively, the multiple temperature image data may be temperature image data from different times or locations that have been generated in advance and stored in the storage unit 58. The detection unit 54 may generate average temperature image data each time temperature image data is generated, or it may generate average temperature image data each time a predetermined number of temperature image data is generated. The state of sputtered SPs (number, location, size, etc. of sputtered SPs on the temperature image data) differs for each temperature image data. Therefore, even if sputtered SPs are detected in one temperature image at the same location on multiple temperature images, sputtered SPs may not necessarily be detected in many other temperature images. In the average temperature image data (average temperature image) generated based on these multiple temperature image data, the locations where sputter SP is detected in one temperature image data (temperature image) are added to and averaged with the locations where sputter SP is not detected in many other temperature image data (temperature images), thereby removing the sputter SP. The average temperature image data (average temperature image) from which sputter SP has been removed includes keyhole KH and molten pool MP.

[0108] Figure 6(c) schematically shows an example of an average temperature image corresponding to the average temperature image data generated by the above process. As shown in Figure 6(c), the average temperature image does not contain any high-temperature regions other than the keyhole KH and molten pool MP. The detection unit 54 takes the difference between the temperature image data (detection target image data) corresponding to the temperature image for detecting sputtered SP shown in Figure 6(a) and the average temperature image data corresponding to the average temperature image shown in Figure 6(c). As a result, as shown in Figure 6(d), an image is generated from the detection target image from which the keyhole KH and molten pool MP have been removed. Since the high-temperature regions on this image are sputtered SP, the detection unit 54 determines at least one of the sputtered SP scattering amount, scattering direction, and scattering velocity based on the high-temperature regions as described above, in the same manner as explained using Figure 6(b). In particular, the detection unit 54 can determine both the sputtered SP and the scattering direction for sputtered SP scattered on the X-direction + side (rearward with respect to the scanning direction of the laser beam) relative to the center of the temperature image.

[0109] Furthermore, the detection unit 54 does not necessarily need to determine the sputtering state from the two-color thermal image data. For example, the acquisition unit 310 may use an imaging device (not shown) instead of the imaging device 41, the bifurcated optical system 42, the chromatic aberration correction optical system 43, and the field aperture 302 to acquire image data of the area to be detected. The imaging device (not shown) may have the same configuration as the imaging device 41 in Figure 1, or it may have another existing configuration. In this case, the detection unit 54 performs existing image processing using the image data acquired by the acquisition unit 310 (imaging device not shown) and detects a circular image of a predetermined size from the image as a sputtering image. The detection unit 54 then determines at least one of the sputtering amount, scattering direction, and scattering velocity from the time change and number of the detected sputtering images.

[0110] Furthermore, the correlation between the state of the spatter SP (amount, direction, and velocity of spatter SP scattering) and the convection C of the molten pool MP, and the correlation between the convection C of the molten pool MP and the melting state of the molten pool MP (information regarding temperature), can be determined. Therefore, the detection unit 54 may (indirectly) determine the melting state of the molten pool MP based on the determined state of the spatter SP. In this case, data regarding the correlation between the state of the spatter SP and the melting state of the molten pool MP is stored in the storage unit 58 in advance.

[0111] <Detection of Hume FU status> The detection unit 54 determines at least one of the fume FU concentration and range as the state of the fume FU from the temperature image data. As described above, since the state of the fume FU is related to the convection C in the melting pool MP, the detection unit 54 can indirectly determine the state of the convection C inside the melting pool MP by determining the state of the fume FU.

[0112] Figure 7 shows an example of a temperature image corresponding to the temperature image data used to determine the state of fume (FU). In Figure 7, the solidification region (BE) is omitted for illustrative purposes. As mentioned above, since fume (FU) is generated from the molten pool (MP) created by irradiation with laser light, the light from the detection target area of ​​the material layer is affected by the fume (FU) and its brightness is reduced. In Figure 7, the shaded areas represent areas where the brightness value is reduced due to the effect of fume (FU). Figure 7(a) is the same temperature image as the one shown in Figure 5. Figure 7(b) schematically shows the original image data corresponding to this temperature image data, i.e., the images corresponding to the image data generated when light of wavelength λ1 and light of wavelength λ2 are incident on different positions on the image sensor 411. In the original image of Figure 7(b), the image D1 caused by light of wavelength λ1 is shown on the left side of the page, and the image D2 caused by light of wavelength λ2 is shown on the right side of the page.

[0113] As described above, the synchrotron radiation from the detection target region of the material layer is affected by fumes (FU), causing a decrease in brightness. Therefore, both image D1 and image D2 show a decrease in brightness. Let's assume that image D1 is brighter (higher brightness) than image D2. However, because light is scattered due to the effect of fumes (FU), the brightness decreases in regions R3 and R4 affected by fumes (FU) in both the bright image D1 and the dark image D2. In this case, the rate of decrease in brightness for the bright image D1 and the dark image D2 is substantially equal. The detection unit 54 distinguishes between the molten pool MP, keyhole KH, and sputter SP and the fumes (FU) based on whether the ratio of brightness values ​​changes between image D1 and image D2. Because fumes (FU) block the light from the molten pool MP, the brightness values ​​of both wavelength λ1 and wavelength λ2 light decrease, but the ratio of brightness values ​​between image D1 and image D2 does not change. In contrast, the ratio of brightness values ​​changes for the molten pool MP, keyhole KH, and sputter SP. Since the brightness information of each pixel in image D1 and image D2 is known, the detection unit 54 can distinguish between the molten pool MP, keyhole KH, and sputter SP and the fume FU based on whether or not there is a change in the ratio of brightness values. The detection unit 54 determines the range of the fume FU (region R3 in image D1 and region R4 in image D2) that has been separated in this way.

[0114] The detection unit 54 determines the density of fume FU by determining the degree of decrease in brightness value using either image D1 or image D2. The detection unit 54 calculates the difference between the brightness value of the fume FU range (region R3 of image D1 or region R4 of image D2) determined as described above and the brightness value of other regions, i.e., regions that are not affected by fume FU and therefore do not experience a decrease in brightness value, and calculates the density of fume FU based on this difference. Data relating the difference in brightness value and the density of fume is stored in the storage unit 58 in advance, and the detection unit 54 refers to this data to calculate the density of fume FU from the calculated difference. The detection unit 54 may also calculate the difference by comparing the brightness value of image D1 or image D2 in image data acquired at a time different from when the image data corresponding to the original image shown in Figure 7(b) was acquired with the brightness value of image D1 or image D2 in the image data of the original image shown in Figure 7(b). Furthermore, since the brightness values ​​of both image D1 and image D2 are reduced due to the influence of Hume FU, the temperature image generated based on the ratio of brightness information of light with wavelength λ1 to brightness information of light with wavelength λ2 is not affected by the obstruction of thermal radiation by Hume FU.

[0115] The detection unit 54 may also determine the state of fume FU using average temperature image data. The average temperature image data is generated in the same manner as described in the process for determining the state of sputter SP. The state of fume FU generation (concentration and range of fume FU on the temperature image data) differs for each temperature image data. Therefore, even if fume FU is detected in one temperature image at the same location on multiple temperature images, it is not necessarily detected in many other temperature images. In the average temperature image data generated by averaging these multiple temperature image data, the influence of fume FU is removed by adding the location affected by fume FU in one temperature image data with the location not affected by fume FU in many other temperature image data and averaging them. The average temperature image data from which fume FU has been removed includes keyhole KH and molten pool MP. In this case, the detection unit 54 generates average temperature image data corresponding to the average temperature image shown in Figure 6(c).

[0116] The detection unit 54 takes the difference between the temperature image data (detection target image data) corresponding to the temperature image for detecting fume FU shown in Figure 7(a) and the average temperature image data. As a result, as shown in Figure 7(c), an image is generated from the detection target image with the keyhole KH and molten pool MP removed. The high-temperature regions on this image (image data) are fume FU and sputter SP. Since sputter SP appears as small granules on the image (image data), the detection unit 54 excludes these granular high-temperature regions from the image data to determine the range of fume FU. In this way, the detection unit 54 determines the diffusion state of fume FU, i.e., the range of fume FU. Since fume FU also has heat, the detection unit 54 determines the temperature of the detected range of fume FU from the image data corresponding to the image shown in Figure 7(c). The higher the temperature, the more fume FU is generated, i.e., the higher the concentration of fume FU. Therefore, the detection unit 54 determines the concentration of fume FU based on the temperature within the determined range of fume FU. In this case, data relating the temperature and concentration of fume FU is pre-stored in the storage unit 58, and the detection unit 54 can refer to this data to determine the concentration of fume FU from the temperature obtained from the image shown in Figure 7(c).

[0117] In the process of determining the state of sputtered SP described above, Figure 6 was used for explanation, omitting fume FU. However, in reality, fume FU is generated, and the temperature image may contain images of fume FU. Therefore, the detection unit 54 separates the molten pool MP, keyhole KH, and sputtered SP from the fume FU using the method described in the process of determining the state of fume FU, and removes the fume FU from the temperature image data (temperature image). The detection unit 54 can then determine the state of sputtered SP from the temperature image data (temperature image) from which the fume FU has been removed using the method described using Figure 6. Alternatively, the detection unit 54 may determine the state of sputtered SP by separating the fume FU from the image data corresponding to the image shown in Figure 7(c), which is generated based on the average temperature image data, based on the difference in area. In this case, an area that can be assumed to be the size of sputtered SP is set in advance as a threshold, and the detection unit 54 determines the area larger than this threshold as fume FU and the area smaller than this threshold as sputtered SP.

[0118] Furthermore, the detection unit 54 does not need to determine the state of the fume FU from the two-color temperature image data. For example, for the acquisition unit 310, instead of the imaging device 41, the bifurcated optical system 42, the chromatic aberration correction optical system 43, and the field aperture 302, an illumination device and an imaging device (not shown) may be used. In this case, as an example, in the space between the base plate 311 and the molding optical system 35, the illumination device is placed on the X-direction + side with respect to the center of the base plate 311 in Figure 1, and the imaging device is placed on the X-direction - side. The illumination device and the imaging device are placed opposite each other so that the illumination light from the illumination device is received by the imaging device. As an example, the illumination device (not shown) is an existing surface-emitting LED, and the imaging device (not shown) has the same configuration as the imaging device 41 in Figure 1.

[0119] Here, when fume FU is generated in the space between the base plate 311 and the molding optical system 35 due to laser irradiation, the illumination light from the illumination device is scattered by the fume FU and received by the imaging device. In other words, the intensity of the light received through the area where fume FU is generated is lower than the intensity of the light received through the area where fume FU is not generated. Therefore, the detection unit 54 can determine the area where fume is generated by comparing the signal intensity of each pixel in the image data generated by the imaging device with a predetermined threshold. Furthermore, the higher the concentration of fume FU, the greater the effect of scattering by fume FU, and the greater the intensity of the illumination light from the illumination device. Therefore, the detection unit 54 can determine the concentration (concentration distribution) of fume FU based on the signal intensity of each pixel in the image data generated by the imaging device.

[0120] Furthermore, the acquisition unit 310 may consist of sets of illumination devices and imaging devices (not shown) arranged in different orientations (for example, illumination devices may be placed on the X-direction + side and Y-direction + side with respect to the center of the base plate 311, and imaging devices may be placed on the X-direction - side and Y-direction - side), and the detection unit 54 may determine the spatial range and spatial density (density distribution) where fumes FU are being generated based on the signal intensity of each pixel in the image data generated by each imaging device.

[0121] Note that the lighting device not shown does not have to be a surface-emitting LED; other existing configurations may be used as long as they can emit light from a surface in a space where fume (FU) may be generated. Alternatively, the device does not have to emit light from a surface, and an existing point-emitting lighting device may be used. Furthermore, the correlation between the state of the fume FU (range and concentration of sputtered sputter SP) and the convection C of the molten pool MP, and the correlation between the convection C of the molten pool MP and the melting state of the molten pool MP (information on temperature), can be determined. Therefore, the detection unit 54 may (indirectly) determine the melting state of the molten pool MP based on the determined state of the fume FU. In this case, data regarding the correlation between the state of the fume FU and the melting state of the molten pool MP is stored in the storage unit 58 in advance.

[0122] (2) Process to change the molding conditions Based on the state of the target area to be detected determined by the detection unit 54 as described above, the calculation unit 56 sets the values ​​of the parameters included in each of the above equations (1) to (3) so that at least one of the values ​​of power density PD, energy density ED, and temperature distribution T(r) is kept within the desired range, if a change in the molding conditions is necessary. A change in the molding conditions is necessary when molding with the currently set molding conditions may result in molding defects such as insufficient melting, shape abnormalities, or failure to obtain the desired metal crystals in the three-dimensional molded object. Whether or not a change in the molding conditions is necessary is determined by the determination unit 57. The determination unit 57 determines that a change in the molding conditions is necessary if the state of the target area to be detected determined by the detection unit 54 satisfies the standard range described later.

[0123] The calculation unit 56 generates modification information, which is information for changing the molding conditions so that they match the set parameter values. In this embodiment, the following (2-1) to (2-7) are examples of molding conditions to be changed. (2-1) Conditions of the laser light emitted toward the powder material P of the material layer, i.e., conditions related to the irradiation unit 32 (2-2) Scanning conditions for scanning the material layer with laser light, i.e., conditions related to the scanning unit 33 (2-3) Conditions related to the atmosphere inside the enclosure 10 (2-4) Conditions for forming a material layer (2-5) Support conditions related to the base plate 311 of the molding tank 31 (2-6) Design information (design data) regarding the shape of the solidified layer or three-dimensional object. (2-7) Conditions related to powder material P

[0124] Specific examples of the molding conditions (2-1) to (2-7) above are shown below. As an example, Figures 8 and 9 show the relationship between the main printing conditions, the basic conditions of power density PD, energy density ED, and temperature distribution T(r), and the parameters shown in equations (1) to (3). In Figures 8 and 9, basic conditions that can be controlled by each printing condition are indicated with a circle (○), and basic conditions that cannot be controlled or whose control has little effect are indicated with a blank space (blank). Also, Figures 8 and 9 show the parameters in equations (1) to (3) that are related to each printing condition. As a note, Figures 8 and 9 show at which timing each printing condition can be changed: in real time, during next layer printing, or during next object printing.

[0125] (2-1) Conditions related to the irradiation unit 32 As a specific example of the fabrication conditions related to the conditions of the laser light emitted from the irradiation unit 32, as shown in Figure 8, there is at least one condition of the laser light output [W] (laser power), the laser light wavelength [nm], the laser light intensity distribution (profile), and the size of the laser light beam [mm] (spot size).

[0126] The laser output affects the amount of heat transferred to the powder material P irradiated by the laser light emitted from the laser oscillator 321. The higher the laser output, the greater the amount of heat absorbed by the powder material P. The laser output is related to the parameter P described above. L These are the molding conditions for which modification information is generated in relation to the above. As mentioned above, when the laser output is increased, the values ​​of power density PD, energy density ED, and temperature distribution T(r) increase. The modification information for changing the laser output is the new output value of the laser light emitted from the irradiation unit 32, or a correction value to the currently set output value of the laser light.

[0127] The wavelength of the laser light is related to the absorption rate of the powder material P. Generally, it is known that the shorter the wavelength of the laser light, the higher the absorption rate of the powder material P. In other words, the wavelength of the laser light is a fabrication condition for which modification information is generated in relation to the parameter η, and the value of parameter η decreases as the wavelength of the laser light increases. For this reason, the wavelength of the laser light affects the values ​​of power density PD and energy density ED. Modification information for changing the wavelength of the laser light is, for example, information indicating which wavelength of laser light to emit from among the wavelengths that can be emitted as laser light.

[0128] In this embodiment, as described above, the intensity distribution (profile) of the laser beam can be switched between a Gaussian distribution and a top-hat distribution. The intensity distribution of a Gaussian distribution laser beam is strongest near the central axis of the laser beam and gradually weakens towards the periphery. The intensity distribution of a top-hat distribution laser beam is more uniform even in the peripheral areas far from the central axis of the laser beam, compared to a Gaussian distribution laser beam. As a result, with a top-hat distribution laser beam, the laser beam with the intensity necessary to melt the powder material P is irradiated over a wider area of ​​the material layer compared to a Gaussian distribution laser beam. Therefore, the intensity distribution of the laser beam affects the spot size of the laser beam on the upper surface of the material layer. In other words, the intensity distribution of the laser beam is a molding condition for which change information is generated in relation to parameter d. When the intensity distribution of the laser beam is switched to a top-hat distribution, the spot size increases, and the amount of heat flowing into the powder material P per unit area on the material layer due to laser irradiation decreases. Therefore, when the intensity distribution is set to a top-hat distribution, the value of parameter d increases, and the values ​​of power density PD and energy density ED decrease.

[0129] In a Gaussian-distributed laser beam, the intensity distribution is strongest near the central axis of the laser beam. Therefore, compared to a top-hat-distributed laser beam, the laser beam with the intensity necessary to melt the powder material P is irradiated to a narrow area on the material layer. This reduces the spot size and increases the amount of heat flowing into the powder material P per unit area on the material layer due to laser irradiation. Consequently, using a Gaussian-distributed intensity distribution decreases the value of parameter d and increases the values ​​of power density PD and energy density ED. The modification information used to change the intensity distribution of the laser beam is, for example, information indicating whether to emit the laser beam using a Gaussian distribution or a top-hat distribution. The intensity distribution of the laser light is determined by the laser quality [M 2 It is affected by ]. 2 When is 1, the intensity distribution of the laser light becomes a single-mode Gaussian distribution, M 2 The more it changes from 1 (M 2 When d is a value greater than or equal to 1, the intensity distribution of the laser light changes from a single-mode Gaussian distribution. Therefore, the value of parameter d changes depending on the laser quality.

[0130] The spot size of the laser beam affects the area of ​​the material layer irradiated by the laser beam on the XY plane. The smaller the spot size of the laser beam irradiating the upper surface of the material layer, the greater the amount of heat per unit area on the material layer, and the greater the amount of heat flowing into the powder material P per unit area on the material layer due to laser irradiation. As a result, the melting of the powder material P irradiated by the laser beam is promoted, affecting the convection C in the molten pool MP. Therefore, the spot size of the laser beam is a molding condition for which modification information is generated in relation to parameter d. As the spot size increases, parameter d increases, and the amount of heat flowing into the powder material P per unit area on the material layer due to laser irradiation decreases, so the values ​​of power density PD and energy density ED decrease. The spot size affects the value of the temperature distribution T(r). Modification information for changing the spot size of the laser beam is, for example, the position of the concave lens 323a of the focus lens 323 in the X direction, or the amount of movement from the current position of the concave lens 323a. The wavelength of the laser beam can be changed when creating the next object. Other printing conditions can be changed in real time, when creating the next layer, or when creating the next object.

[0131] (2-2) Conditions related to the scanning unit 33 Specific examples of fabrication conditions for scanning a material layer with laser light include the scanning speed of the laser light [mm / s], the distance between two adjacent laser beam irradiation positions in a direction intersecting the scanning direction of the laser light (scanning pitch) [mm], and at least one of the scanning path of the laser light. The scanning speed of the laser beam is related to the time the laser beam is irradiated per unit area of ​​the material layer surface, and affects the amount of heat flowing into the powder material P per unit area of ​​the material layer due to laser irradiation, as well as the temperature change (temperature gradient) in the molten pool MP as the position of the laser beam changes. When the scanning speed of the laser beam is high, the amount of heat flowing into the powder material P per unit area of ​​the material layer surface due to laser irradiation decreases. When the scanning speed of the laser beam is low, the amount of heat flowing into the powder material P per unit area of ​​the material layer surface due to laser irradiation increases. The scanning speed of the laser beam is a molding condition for which change information is generated in relation to the above parameter v. As the scanning speed increases, parameter v also increases, and the values ​​of power density PD, energy density ED, and temperature distribution T(r) decrease. Change information for changing the scanning speed includes, for example, a new change speed for the tilt angle of the galvanometer mirrors 331 and 332, and a correction value for the change speed of the currently set tilt angle.

[0132] When the scanning pitch is small, the influence of heat from adjacent solidification regions BE already formed by laser irradiation is significant. Consequently, the initial temperature of the powder material P that is not irradiated by the laser increases, and the amount of heat required to reach the desired temperature (e.g., melting point) decreases. In other words, the smaller the scanning pitch, the greater the heat absorption rate of the powder material P, and the larger the scanning pitch, the smaller the heat absorption rate of the powder material P. Furthermore, when the scanning pitch is small, heat from a direction different from the scanning direction of the laser beam affects the convection C in the molten pool MP.

[0133] When the scanning pitch is large, the influence of heat from adjacent solidification regions BE already formed by laser irradiation is small, so the amount of heat required to raise the initial temperature of the powder material P that has not been irradiated by the laser to the desired temperature (e.g., melting point) increases. The scanning pitch is a build condition in which modification information is generated in relation to the parameters η and Δy. When the scanning pitch is large, the value of parameter η is small, the value of parameter Δy is large, and the value of energy density ED is small. The scanning pitch affects the values ​​of power density PD and temperature distribution T(r). Modification information for changing the scanning pitch is, for example, a new setting angle to be changed from the current setting angle of galvanometer mirrors 331 and 332, or a correction value to change from the current setting angle to the new setting angle.

[0134] The laser beam scanning path is a fabrication condition that specifies the path for irradiating the surface of the material layer with laser light. Examples of scanning paths include irradiating the laser beam along the contour of the shape (fabricated model) based on slice model data, and then irradiating the inside of the contour, or irradiating the inside of the contour of the shape (fabricated model) based on slice model data, and then irradiating the laser beam along the contour of the shape (fabricated model) based on slice model data. Furthermore, the laser beam scanning path is determined based on the initial temperature T0 of the material layer before laser irradiation, for example, to ensure that residual stress is less likely to occur in the solidified layer fabricated by the laser.

[0135] As an example of the laser beam scanning path, if the laser beam is irradiated along the contour of the shape (molded model) based on slice model data, as illustrated above, and then the laser beam is irradiated into the contour, the initial temperature of the powder material P inside the contour rises due to the diffusion of heat from the laser beam that has already been irradiated onto the contour of the shape (molded model) based on slice model data. Therefore, the laser beam scanning path is a molding condition in which change information is generated in relation to the parameter P0 depending on the scanning path to be changed, and it affects the values ​​of power density PD, energy density ED, and temperature distribution T(r). Change information for changing the scanning path is, for example, the new tilt angle values ​​of the galvanometer mirrors 331 and 332 and the timing information for setting those tilt angle values. Each of the above printing conditions can be changed in real time, during the printing of the next layer, or during the printing of the next object.

[0136] (2-3) Conditions related to the atmosphere inside the enclosure 10 As a specific example of using the internal atmosphere of the enclosure 10 as a molding condition, the flow rate of the inert gas introduced into the enclosure 10 [mm²] 3 There is at least one of the following conditions: the flow rate of the inert gas introduced into the housing 10 [mm / s], and the temperature inside the housing 10 [°C]. In this embodiment, the flow rate and velocity of the inert gas affect the initial temperature of the material layer before laser irradiation and the fumes FU generated from the powder material P by laser irradiation. For example, if the flow rate or velocity of the inert gas is high, the surface of the material layer is cooled by the inert gas, increasing the amount of heat required for the temperature of the powder material P irradiated with laser light to rise to the desired temperature (e.g., melting point). Therefore, the flow rate and velocity of the inert gas affect the initial temperature of the powder material P before it is irradiated with laser light, and thus are molding conditions related to parameter P0.

[0137] Furthermore, if the inert gas flow rate or velocity is low, for example, fumes FU generated by laser irradiation remain near the laser irradiation position, obstructing the optical path of the laser beam toward the material layer. As a result, the amount of heat flowing into the powder material P due to laser irradiation decreases, potentially resulting in a melting state different from the expected one. Therefore, the inert gas flow rate and velocity are molding conditions related to parameter η, as they affect the absorption rate when the powder material P absorbs heat from laser irradiation. The inert gas flow rate and velocity are molding conditions for which change information is generated in relation to parameters P0 and η. For example, when the inert gas flow rate increases and the velocity rises, the value of parameter P0 decreases, the value of parameter η increases, and the value of the temperature distribution T(r) decreases. The inert gas flow rate and velocity affect the values ​​of power density PD and energy density ED. Change information for changing the inert gas flow rate and velocity includes, for example, a new valve opening for the intake device 131, a new exhaust volume for the exhaust device 14, or correction values ​​for the currently set valve opening or exhaust volume.

[0138] The temperature inside the housing 10 affects the initial temperature of the material layer before laser irradiation and is a molding condition for which modification information is generated in relation to the parameter P0. The higher the temperature inside the housing 10, the warmer the powder material P is and the higher its initial temperature, so the amount of heat required for the temperature of the powder material P to rise to the desired temperature (e.g., melting point) by laser irradiation is reduced. Therefore, the temperature inside the housing 10 affects the initial temperature of the powder material P before it is irradiated with laser light and is a molding condition related to the parameter P0. For example, as the temperature inside the housing 10 increases, the value of parameter P0 increases, and the values ​​of power density PD, energy density ED, and temperature distribution T(r) increase. Modification information for changing the temperature inside the housing 10 is, for example, a new heating output value for the heater 15 or a correction value for the currently set heating output of the heater 15.

[0139] The temperature inside the housing 10 can be changed when the next layer is being fabricated or when the next object is being fabricated. The flow rate and velocity of the inert gas introduced into the housing 10 can be changed in real time, when the next layer is being fabricated, or when the next object is being fabricated.

[0140] (2-4) Conditions for forming a material layer Specific examples of molding conditions for forming a material layer include the moving speed of the blade 221 [mm / s], the pressure [Pa] applied by the blade 221 to the powder material P, the time [s] the blade 221 waits after forming the solidified layer before starting to form a new material layer on top of the solidified layer, the shape of the blade 221, the material of the blade 221, and at least one of the following conditions [mm] of the layer thickness of the material layer on the base plate 311.

[0141] The movement speed of the blade 221 and the pressure applied by the blade 221 to the powder material P affect the flatness of the surface of the formed material layer, as well as the thickness and density of the material layer. For example, when the movement speed of the blade 221 is fast, the flatness of the surface of the material layer decreases, the thickness increases, and the density decreases compared to when the movement speed of the blade 221 is slow. Also, when the pressure applied by the blade 221 to the powder material P is high, the flatness of the surface of the material layer increases, the thickness decreases, and the density increases compared to when the pressure is low. Therefore, the movement speed of the blade 221 is a molding condition that affects the parameters Δz, ρ, k, and α. For example, when the movement speed of the blade 221 is changed, the values ​​of energy density ED and temperature distribution T(r) are affected. The pressure applied by the blade 221 to the powder material P is a molding condition that generates change information in relation to the parameters Δz, ρ, k, and α. For example, when the pressure increases, the values ​​of parameters ρ, k, and α increase, the value of parameter Δz decreases, and the values ​​of energy density ED and temperature distribution T(r) increase. The change information for changing the moving speed of the blade 221 is a new value for the motor output of the drive mechanism that moves the blade 221, or a correction value for the currently set motor output. The change information for changing the pressure that the blade 221 applies to the powder material P may be, for example, a new drive amount value for the pressing mechanism, or a correction value for the currently set drive amount of the pressing mechanism.

[0142] As described above, the waiting time for blade 221 is the time from when the laser beam irradiation of the material layer for the formation of the solidified layer is completed until blade 221 starts transferring the powder material P from the material supply tank 21 to the molding tank 31. The waiting time for blade 221 affects the initial temperature of the new material layer formed on top of the solidified layer. That is, the longer the waiting time, the lower the temperature of the solidified layer, which has risen due to the laser beam irradiation, so the lower the initial temperature of the new material layer formed on top of that solidified layer becomes. In this case, the amount of heat required to raise the temperature of the powder material P irradiated with laser beam to the desired temperature (e.g., melting point) increases. Therefore, the waiting time for blade 221 is a molding condition for which change information is generated in relation to parameter P0. For example, as the waiting time increases, the value of parameter P0 decreases, and the values ​​of power density PD, energy density ED, and temperature distribution T(r) decrease. The change information for modifying the waiting time of the blade 221 includes, for example, a value indicating the timing of the motor start-up of the drive mechanism that moves the blade 221, and a correction value for the currently set motor start-up timing.

[0143] If, for example, there is a defect in the blade 221, the thickness of the material layer will not be constant depending on the shape of the defect, resulting in a decrease in flatness, a difference in the laminate thickness from the desired thickness, uneven density within the material layer, and increased surface roughness. Furthermore, even if there is no defect in the blade 221, if the shape of the blade 221 changes, the contact area of ​​the blade 221 with the powder material P changes, and therefore the density, flatness, and laminate thickness of the material layer change according to that shape. Depending on the characteristics of the material of the blade 221 and the material (type) of the powder material P, factors such as friction may hinder the movement of the blade 221, preventing the powder material P from being uniformly transported onto the base plate 311 and solidification layer, which may result in a decrease in the flatness of the formed material layer, a difference in the laminate thickness from the desired thickness, a decrease in the uniformity of density within the material layer, and increased surface roughness. Therefore, the shape and material of the blade 221 are fabrication conditions that affect the parameters Δz, ρ, k, and α, and when the shape and material of the blade 221 are changed, the values ​​of the energy density ED and the temperature distribution T(r) are affected.

[0144] The shape and material of the blade 221 can be changed by changing the type of blade 221. In this case, the change information for changing the shape and material of the blade 221 is, for example, information indicating that the blade 221 needs to be replaced. In this case, the molding apparatus 1 provides notification prompting the replacement of the blade 221. As a method of notification, the molding apparatus 1 may display a message on a monitor (not shown) indicating that the type of inert gas needs to be changed, or emit an audio message from a speaker (not shown). Furthermore, if the blade 211 has a configuration that allows for automatic replacement between multiple types, the type of blade 211 is automatically replaced according to the control from the material control unit 51. Also, if the shape of the blade 221 has a variable structure as described above, the shape of the blade 221 can be changed according to the control from the material control unit 51. In this case, the change information generated is, for example, information instructing a change in the shape of the blade 221.

[0145] When the thickness of the material layer is thick, the amount of heat generated by the irradiation of the laser beam may not sufficiently reach the Z-side surface (bottom surface) of the material layer, which can cause molding defects such as insufficient melting. The layer thickness is a molding condition for which change information is generated in relation to the parameter Δz. For example, as the layer thickness increases, the value of the parameter Δz increases, and the value of the energy density ED decreases. The change information for changing the layer thickness may be, for example, a new pressure value applied by the blade 221 of the recoater 22 to the powder material P, or a correction value for the current pressure, or a new drive amount value for the pressing mechanism of the blade 221, or a correction value for the currently set drive amount of the pressing mechanism. The shape and material of the blade 221 can be changed during the next molding process. The blade 221's movement speed, the pressure applied to the powder material P, the waiting time, and the thickness of the material layer can be changed during the next layer molding process or when the next molding process is performed.

[0146] (2-5) Support conditions related to the base plate 311 of the molding tank 31 The molding conditions related to the base plate 311 of the build tank 31 include the temperature of the base plate 311 [°C]. The temperature of the base plate 311 affects the initial temperature of the material layer formed on top, and the higher the temperature of the base plate 311, the warmer the powder material P becomes. Therefore, the higher the temperature of the base plate 311, the higher the initial temperature of the powder material P. In this case, the amount of heat required to raise the temperature of the powder material P irradiated with laser light to a desired temperature (e.g., melting point) decreases. Thus, the temperature of the base plate 311 is a molding condition for which modification information is generated in relation to the parameter P0. When the temperature of the base plate 311 is high, the value of parameter P0 increases, and the values ​​of power density PD, energy density ED, and temperature distribution T(r) increase. Modification information for changing the temperature of the base plate 311 is, for example, a new heating output value for the heater 313 or a correction value for the currently set heating output of the heater 313.

[0147] Furthermore, if the temperature of the base plate 311 is high, the amount of temperature decrease when the temperature of the solidified layer, which has risen due to laser irradiation, decreases, thus reducing the influence of residual stress generated when the molten pool MP solidifies. Also, as mentioned above, if the temperature of the base plate 311 is high, less heat is required for the temperature of the powder material P irradiated with laser light to rise to the desired temperature, so it becomes possible to increase the scanning speed without changing the laser output. The temperature of the base plate 311 can be changed when printing the next layer or when printing the next object.

[0148] (2-6) Design data related to the shape of the solidified layer or three-dimensional object A specific example of using design data related to the shape of the solidified layer or the three-dimensional object as a printing condition is that there is at least one data set, which is the shape data of the solidified layer to be printed (slice model data) and the shape data of the support parts that support the solidified layer or the three-dimensional object.

[0149] Slice model data is shape data used to determine the shape of the solidified layer to be fabricated on the XY plane, the thickness of the solidified layer (slice pitch), etc. Slice model data is fabrication condition for which change information is generated in relation to the parameter Δz. That is, as the thickness of the solidified layer increases, the value of the parameter Δz increases. When the slice model data, which is shape data, is changed, various fabrication conditions for the laser beam from the irradiation unit 32 and various fabrication conditions for scanning by the scanning unit 33 may be changed, so the slice model data affects the values ​​of power density PD, energy density ED, and temperature distribution T(r). Change information for changing slice model data includes, for example, a new shape of the solidified layer on the XY plane, a new thickness of the solidified layer, or correction values ​​for the shape of the solidified layer on the XY plane and correction values ​​for the thickness of the solidified layer.

[0150] As described above, the shape data of the support section indicates the shape, such as the thickness and length, of the support section that supports the three-dimensional object to prevent deformation and damage between solidified layers and the three-dimensional object. The shape of the support section is determined by the shape and size of the solidified layer and the three-dimensional object it supports. The larger the volume of the support section, the greater the influence of the heat from the part of the solidified layer that is formed by laser irradiation as the support section on the material layer (powder material P) formed on top of that solidified layer. Also, the higher the initial temperature of the powder material P when heated by the base plate 311, the greater the amount of heat transferred from the base plate 311 to the material layer (powder material P) through the part of the solidified layer that is formed as the support section. For this reason, the shape data of the support section is a molding condition that affects the parameter P0 depending on the volume of the support section and the temperature of the base plate 311, and affects the values ​​of energy density ED and temperature distribution T(r). Change information for modifying the shape data of the support section is, for example, the value of the new shape of the support section (length, thickness, etc.) or the correction value of the current shape of the support section (length, thickness, etc.). Slice model data and support member shape data can be corrected when modifying the next printed object.

[0151] (2-7) Conditions related to powder material P Specific examples of molding conditions related to powder material P include the particle size / particle size distribution of powder material P, the moisture absorption of powder material P, and at least one of the types of powder material P. Variations in the particle size and particle size distribution of the powder material P within the material layer can affect the thermal diffusivity and thermal conductivity of the material layer irradiated with laser light, potentially causing melting defects. Furthermore, when powder material P with variations in particle size and particle size distribution is transferred to the molding tank 31 by the blade 221, variations in thickness and density may occur in the material layer, potentially resulting in defects such as voids in the solidified layer. Particle size and particle size distribution are molding conditions for which modification information is generated in relation to the parameters Δz, ρ, k, and α. For example, as the particle size and particle size distribution increase (the variation increases), the value of parameter Δz increases, the values ​​of parameters ρ, k, and α decrease, and the values ​​of energy density ED and temperature distribution T(r) increase. Modification information for changing the particle size and particle size distribution of the powder material P is, for example, information instructing the removal of the formed material layer and the formation of a new material layer.

[0152] Highly hygroscopic powder material P has low fluidity and is difficult to smoothly transfer to the build tank 31 by the blade 221. Therefore, the flatness and thickness of the formed material layer are less uniform, and surface roughness tends to increase. In other words, the hygroscopicity of powder material P is a build condition that affects the parameter Δz. Furthermore, high hygroscopicity of powder material P makes it difficult to achieve uniform flatness, thickness, and density of the material layer, resulting in uneven temperature rise due to laser irradiation and potentially causing defects such as voids in the solidified layer due to poor melting. Additionally, high hygroscopic powder material P has low thermal conductivity and thermal diffusivity, which can lead to defects such as voids in the solidified layer due to poor melting. Therefore, the hygroscopicity of powder material P is a build condition that generates change information related to the parameters k and α. For example, high hygroscopicity of powder material P lowers the values ​​of parameters k and α, and decreases the value of the temperature distribution T(r). Also, the hygroscopicity of powder material P affects the values ​​of power density PD and energy density ED. The information used to change the humidity absorption includes, for example, information indicating that the powder material P needs to be heated by the heater 213, and the value of the heating output of the heater 213.

[0153] There are different types of powder materials P, each with different powder materials and additives. Different types of powder materials P result in differences in particle size, thermal conductivity, thermal diffusivity, etc. Furthermore, even if the same pressure is applied to powder materials P of different particle sizes with the blade 221 when forming a material layer, using a powder material P with larger particle sizes will result in larger gaps between particles within the material layer compared to using a powder material P with smaller particle sizes, thus increasing the layer thickness and lowering the density of the material layer. Therefore, the type of powder material P is a molding condition that affects the parameters Δz, ρ, k, and α, and affects the energy density ED and temperature distribution T(r). Change information for changing the type of powder material P is, for example, information indicating the use of a different type of powder material P. In this case, the molding device 1 will, for example, notify the user to change the powder material P. As a method of notification, the molding device 1 may display a message on a monitor (not shown) indicating that the type of powder material P needs to be changed, or emit an audio message from a speaker (not shown). Furthermore, if each of the multiple material supply tanks 21 contains a different type of powder material P, and the multiple material supply tanks 21 are configured to be automatically replaceable, the type of powder material P is automatically changed when the material supply tank 21 is replaced according to the control from the material control unit 51.

[0154] The particle size, particle size distribution, and type of the powder material P can be changed when modifying the next object. The moisture absorption of the powder material P can be corrected when modifying the next layer or when modifying the next object. In the explanation using Figures 8 and 9 above, the relevant parameters were exemplified as those that are particularly relevant to each of the molding conditions included in (2-1) to (2-7) above and that change significantly with changes in the molding conditions. However, when each molding condition is changed, parameters other than those exemplified above, among the parameters included in equations (1) to (3), will also be affected. Therefore, taking into account the changes in parameters other than those exemplified above, change information may be generated to modify the molding conditions so that at least one of the power density PD, energy density ED, and temperature distribution T(r) falls within the desired range.

[0155] In this embodiment, the molding conditions may include, in addition to the molding conditions (2-1) to (2-8) described above, other existing molding conditions in the molding apparatus 1. Other molding conditions include the oscillation mode of the laser light from the irradiation unit 32, the polarization state of the laser light, the type of inert gas, the oxygen concentration inside the housing 10, the pressure [Pa] inside the housing 10, the type of base plate 311, molding orientation data, the shape data of the three-dimensional molded object, and the oxygen concentration of the powder material P.

[0156] As described above, in this embodiment, the laser light oscillation mode can be switched between CW (continuous wave) oscillation and pulsed oscillation. In the case of pulsed oscillation, the on-time is shorter than in CW oscillation, so the amount of heat absorbed by the powder material P at the irradiated position of the laser light is smaller compared to the case of CW oscillation. Therefore, depending on the oscillation mode, there is a difference in the amount of heat flowing into the powder material P, which affects the melting of the powder material P, and it is known that this particularly affects the depth of the keyhole KH and the width of the solidification region BH. In other words, the oscillation mode affects the values ​​of power density PD, energy density ED, and temperature distribution T(r). The change information for changing the laser light oscillation mode is, for example, information indicating whether to emit the laser light in CW (continuous wave) oscillation mode or pulsed oscillation mode. The laser light oscillation mode can be changed in real time, during the next layer fabrication, or during the fabrication of the next object.

[0157] Laser light can be polarized in various ways, such as circularly polarized or linearly polarized. When the powder material P is a metallic material, the absorption of the laser light is affected by the polarization state of the laser light. In other words, the polarization state of the laser light affects the amount of heat that flows into the powder material P irradiated with the laser light. Therefore, the polarization state of the laser light is a molding condition that affects at least one of the power density PD, energy density ED, and temperature distribution T(r). The information for changing the polarization state of the laser light is, for example, information indicating which of the configurable polarization states (e.g., circularly polarized or linearly polarized) to set for the laser light emitted from the irradiation unit 32. The polarization state of the laser light can be changed when changing the settings for the next molding process.

[0158] The type of inert gas can be selected from options such as nitrogen or argon. The type of inert gas is a molding condition selected according to the type of powder material P. For example, if the powder material P is titanium, using nitrogen as the inert gas will cause the powder material P to react with the nitrogen, so it is better to use argon as the inert gas. In this way, if an appropriate inert gas is not selected for the type of powder material P, the powder material P and the inert gas will react, affecting the values ​​of power density PD, energy density ED, and temperature distribution T(r). The information for changing the type of inert gas is information indicating that a different type of inert gas is to be used. In this case, the molding device 1 will, for example, notify the user to change the inert gas. As a method of notification, the molding device 1 may display a message on a monitor (not shown) indicating that the type of inert gas needs to be changed, or emit an audio message from a speaker (not shown). The type of inert gas can be changed by replacing the tank 13. Furthermore, if multiple tanks 13 contain different types of inert gases and the multiple tanks 13 are configured to be automatically replaceable, the type of inert gas is automatically changed when a tank 13 is replaced according to the control from the housing control unit 53. The type of inert gas can be changed when changing it for the next molding process.

[0159] The oxygen concentration inside the housing 10 is a molding condition set to a concentration that prevents oxidation of the material layers during molten and solidified states. As described above, an oxide film is formed on the surface of the oxidized powder material P, and the specific heat changes according to the thickness of the oxide film, affecting the heat absorption and conduction of the powder material P. Therefore, the oxygen concentration inside the housing 10 is a molding condition that affects the values ​​of the energy density ED and the temperature distribution T(r). The information used to change the oxygen concentration inside the housing 10 is, for example, a new valve opening of the intake device 131, a new exhaust volume of the exhaust device 14, or correction values ​​for the currently set valve opening or exhaust volume. The oxygen concentration inside the housing 10 can be changed when changing the next layer or when changing the next object.

[0160] Since the three-dimensional object is fabricated while the inside of the enclosure 10 is maintained at a predetermined pressure, the pressure inside the enclosure 10 is controlled as a fabrication condition. The pressure inside the enclosure 10 affects the surface tension of the molten pool MP. As described above, the convection C inside the molten pool MP is caused by the difference in surface force between the surface and the interior of the molten pool MP, so the pressure inside the enclosure 10 is a fabrication condition that affects the convection C of the molten pool MP. Since the convection C affects the temperature distribution inside the molten pool MP, the pressure inside the enclosure 10 is a fabrication condition that affects the temperature distribution T(r). The information for changing the pressure inside the enclosure 10 is, for example, a new exhaust volume of the exhaust device 14, or a correction value for the currently set exhaust volume. The pressure inside the enclosure 10 can be changed when fabricating the next layer or when fabricating the next object.

[0161] As described above, the build orientation data indicates the build orientation of the solidified layer and the three-dimensional object, and is used when setting the slice model data. When the build orientation is changed, various build conditions for the laser beam from the irradiation unit 32 and various build conditions for scanning by the scanning unit 33 may change. For this reason, the build orientation data affects the values ​​of power density PD, energy density ED, and temperature distribution T(r). Change information generated for the build orientation data is, for example, information indicating the slice direction when the new build orientation is set. The build orientation data can be changed when changing it for the next build.

[0162] The shape data of a three-dimensional object is design data (i.e., CAD data or STL data). Therefore, if the shape data of the three-dimensional object is changed, the various printing conditions for the laser beam from the irradiation unit 32 and the various printing conditions for scanning by the scanning unit 33 may also be changed. For this reason, the shape data of the three-dimensional object affects the values ​​of power density PD, energy density ED, and temperature distribution T(r). Change information for modifying the shape data of the three-dimensional object includes, for example, a value indicating the new shape of the three-dimensional object and a correction value for the current shape of the three-dimensional object. The shape data of the three-dimensional object can be corrected when it is modified during the next printing process.

[0163] As described above, in this embodiment, the base plate 311 is configured to be selectable and attachable from multiple types with different thicknesses and materials. The type of base plate 311 is a molding condition for selecting a base plate 311 that has the necessary rigidity (thickness and material) to prevent deformation of the solidified layer due to residual stress generated when the molten pool MP solidifies and to maintain the shape of the solidified layer. Since residual stress is generated according to the temperature change until the molten powder material P solidifies, the type of base plate 311 for suppressing the generation of residual stress is a molding condition related to the temperature distribution T(r). The base plate 311 can be changed when the next object is molded. Change information for changing the type of base plate 311 is, for example, information indicating the use of a different type of base plate 311. In this case, the molding device 1 notifies the user, for example, to change the base plate 311. As a method of notification, the molding device 1 may display a message on a monitor (not shown) that it is necessary to change the type of base plate 311, or emit an audio message from a speaker (not shown). Furthermore, if the base plate 311 has a configuration that allows for automatic exchange between multiple types, the type of base plate 311 is automatically exchanged according to the control from the molding control unit 52.

[0164] When the powder material P oxidizes, an oxide film is formed on the surface of the powder material P as described above, and the specific heat changes depending on the thickness of the oxide film. The oxide film on the powder material P affects the heat conduction of the powder material P and may cause melting defects, etc. Therefore, the oxygen concentration of the powder material P becomes a molding condition and affects the value of the energy density ED. The change information generated for the oxygen concentration of the powder material P includes, for example, information indicating that the powder material P needs to be heated by the heater 213 and the value of the heating output of the heater 213. The oxygen concentration of the powder material P can be changed when changing it for the next molding.

[0165] Next, a specific example of the change information generated by the calculation unit 56 will be described. In the following description, an example will be given in which the calculation unit 56 generates change information in order to keep at least one of the power density PD, energy density ED, and temperature distribution T(r) within a desired range.

[0166] Based on the state of the detection target area determined by the detection unit 54, parameter P L This section explains when the parameter P is changed. L When increasing the parameter P, that is, when increasing the value of power density PD, energy density ED, or temperature distribution T(r), the calculation unit 56 generates modification information to increase the laser output of the laser beam from the irradiation unit 32, for example. L When reducing the values ​​of power density PD, energy density ED, or temperature distribution T(r), the calculation unit 56 generates modification information to lower the laser output of the laser beam from the irradiation unit 32. The modification information generated in this case is the output value of the laser beam emitted from the irradiation unit 32. The output unit 55 outputs the generated modification information as status information to the molding control unit 52 of the setting unit 59. The molding control unit 52, for example, changes the set laser beam output value to the output value indicated by the modification information and emits the laser beam from the irradiation unit 32 at the modified output value. Parameter P L Data relating the value of and the laser output is pre-stored in the storage unit 58. The calculation unit 56 uses this data to determine the parameter P LThe laser output value corresponding to the desired value is read out, and the read-out new laser output value is generated as change information.

[0167] The following describes the case in which parameter P0 is changed based on the state of the detection target area determined by the detection unit 54. When parameter P0 is increased, that is, when the value of power density PD, energy density ED, or temperature distribution T(r) is increased, the calculation unit 56 generates change information so that at least one of the following changes to the molding conditions is made. In this case, changes to the molding conditions include, for example, a decrease in the flow rate and flow velocity of the inert gas, an increase in the temperature inside the housing 10, a reduction in the waiting time of the blade 221, and an increase in the temperature of the base plate 311. When parameter P0 is decreased, that is, when the value of power density PD, energy density ED, or temperature distribution T(r) is decreased, the calculation unit 56 generates change information so that at least one of the following changes to the molding conditions is made. In this case, changes to the molding conditions include, for example, an increase in the flow rate and flow velocity of the inert gas, a decrease in the temperature inside the housing 10, an extension of the waiting time of the blade 221, and a decrease in the temperature of the base plate 311.

[0168] If change information is generated to change the flow rate and velocity of the inert gas, the output unit 55 outputs the generated change information as status information to the housing control unit 53 of the setting unit 59. The housing control unit 53, for example, changes the valve opening of the intake device 131 and the exhaust volume of the exhaust device 14 to the valve opening and exhaust volume indicated by the change information, and operates the intake device 131 and exhaust device 14 with the changed valve opening and exhaust volume. If change information is generated to change the temperature inside the enclosure 10, the output unit 55 outputs the generated change information as status information to the enclosure control unit 53. The enclosure control unit 53, for example, changes the set heating output of the heater 15 to the heating output indicated by the change information and operates the heater 15 at the changed heating output.

[0169] If change information is generated to change the waiting time of the blade 221, the output unit 55 outputs the generated change information as status information to the material control unit 51 of the setting unit 59. The material control unit 51, for example, changes the set waiting time to the waiting time indicated by the change information and moves the blade 221 with the changed waiting time. If change information is generated to change the temperature of the base plate 311, the output unit 55 outputs the generated change information as status information to the molding control unit 52 of the setting unit 59. The molding control unit 52, for example, changes the set heating output of the heater 313 to the heating output indicated by the change information and operates the heater 313 at the changed heating output.

[0170] Data relating the value of parameter P0, the flow rate and velocity of the inert gas, the temperature inside the housing 10, the waiting time of the blade 221, and the temperature of the base plate 311 is pre-stored in the storage unit 58. The calculation unit 56 reads the values ​​of each molding condition corresponding to the desired parameter values ​​from this data and generates the read-out new values ​​as change information. Furthermore, since parameter P0 is also affected by the laser beam scanning path and the shape of the support part (such as its thickness and length) depending on the volume of the support part and the temperature of the base plate 311, the calculation unit 56 may generate change information regarding the laser beam scanning path and the shape data of the support part.

[0171] The following describes a case in which the parameter η is changed based on the state of the detection target area determined by the detection unit 54. When the parameter η is increased, that is, when the value of the temperature distribution T(r) is decreased or the value of the energy density ED is increased, the calculation unit 56 generates change information so that at least one of the following changes to the molding conditions is made. In this case, the changes to the molding conditions include changing the wavelength of the laser light to a shorter wavelength, decreasing the scanning pitch, increasing the flow rate of the inert gas, and increasing the flow velocity of the inert gas. On the other hand, when the parameter η is decreased, that is, when the value of the temperature distribution T(r) is increased or the value of the energy density ED is decreased, the calculation unit 56 generates change information so that at least one of the following changes to the molding conditions is made. In this case, changes to the molding conditions include changing the wavelength of the laser light to a longer wavelength, increasing the scanning pitch, and decreasing the flow rate and flow velocity of the inert gas.

[0172] Information regarding the change in the wavelength of the laser light is output to the molding control unit 52 by the output unit 55. The molding control unit 52, for example, changes the set wavelength of the laser light to the wavelength indicated by the change information, and emits laser light from the irradiation unit 32 at the changed wavelength. If change information is generated to change the wavelength of the laser light, the output unit 55 outputs the generated change information as status information to the molding control unit 52 of the setting unit 59. The molding control unit 52, for example, changes the set wavelength of the laser light to the wavelength indicated by the change information and emits laser light from the irradiation unit 32 at the changed wavelength. If change information is generated to change the scanning pitch, the output unit 55 outputs the generated change information as status information to the molding control unit 52 of the setting unit 59. The molding control unit 52, for example, changes the current setting angles of the galvanometer mirrors 331 and 332 to the new setting angles indicated by the change information, and operates the scanning unit 33 at the changed setting angles. If change information is generated to change the flow rate and flow velocity of the inert gas, the output unit 55 outputs the status information to the housing control unit 53 of the setting unit 59, as described above. The housing control unit 53 then operates the intake device 131 and the exhaust device 14, for example, with the valve opening and exhaust volume changed based on the change information. Data relating the parameter η value, scanning pitch, and inert gas flow rate and velocity is pre-stored in the storage unit 58. The calculation unit 56 reads the values ​​of each molding condition corresponding to the desired parameter values ​​from this data and generates the read-out new values ​​as change information.

[0173] The following describes the case in which parameter d is changed based on the state of the detection target area determined by the detection unit 54. When parameter d is increased, that is, when the values ​​of power density PD and energy density ED are decreased, the calculation unit 56 generates change information so that at least one of the following changes to the molding conditions is made. In this case, the changes to the molding conditions include changing the intensity distribution of the laser light to a top-hat distribution and increasing the spot size of the laser light. When parameter d is decreased, that is, when the values ​​of power density PD and energy density ED are increased, the calculation unit 56 generates change information so that at least one of the following changes to the molding conditions is made. In this case, the changes to the molding conditions include changing the intensity distribution of the laser light to a Gaussian distribution and decreasing the spot size of the laser light.

[0174] If change information is generated to modify the intensity distribution of the laser beam, the output unit 55 outputs the generated change information as status information to the molding control unit 52 of the setting unit 59. The molding control unit 52, for example, changes the set intensity distribution of the laser beam to the intensity distribution indicated by the change information and emits laser beam from the irradiation unit 32 with the modified intensity distribution. If change information is generated to change the spot size, the output unit 55 outputs the generated change information as status information to the molding control unit 52 of the setting unit 59. The molding control unit 52, for example, controls a drive mechanism (not shown) to move the concave lens 323a to the position in the X direction indicated by the change information. Data relating parameter d to the laser light intensity distribution and spot size is pre-stored in the storage unit 58. The calculation unit 56 reads the values ​​of each molding condition corresponding to the desired parameter values ​​from this data and generates the read-out new values ​​as change information. Furthermore, when changing parameter d, the calculation unit 56 may generate change information regarding the divergence angle of the laser beam, which affects the intensity distribution of the laser beam.

[0175] The following describes the case in which the parameter v is changed based on the state of the detection target area determined by the detection unit 54. When the parameter v is increased, that is, when the values ​​of power density PD, energy density ED, and temperature distribution T(r) are decreased, the calculation unit 56 generates change information to, for example, increase the scanning speed of the laser beam. When the parameter v is decreased, that is, when the values ​​of power density PD, energy density ED, and temperature distribution T(r) are increased, the calculation unit 56 generates change information to, for example, decrease the scanning speed of the laser beam.

[0176] If change information is generated to change the scanning speed of the laser beam, the output unit 55 outputs the generated change information as status information to the molding control unit 52 of the setting unit 59. The molding control unit 52, for example, changes the set values ​​of the tilt angle change speed of the galvanometer mirrors 331 and 332 to the tilt angle change speed indicated in the change information, and operates the scanning unit 33 at the changed tilt angle change speed. Data relating parameter v to the scanning speed of the laser beam is pre-stored in the storage unit 58. The calculation unit 56 reads the value of the scanning speed corresponding to the desired value of parameter v from this data and generates a new scanning speed for the laser beam as change information.

[0177] The following describes the case in which the parameter Δy is changed based on the state of the detection target area determined by the detection unit 54. When the parameter Δy is increased, that is, when the value of the energy density ED is decreased, the calculation unit 56 generates change information so that the scanning pitch increases. When the parameter Δy is decreased, that is, when the value of the energy density ED is increased, the calculation unit 56 generates change information so that the scanning pitch decreases. As described above, the generated change information is output as state information to the molding control unit 52 of the setting unit 59 by the output unit 55. The molding control unit 52 changes the setting angle to the new setting angle indicated by the change information, for example, and operates the scanning unit 33 at the changed setting angle. Data relating the parameter Δy to the scanning pitch is pre-stored in the storage unit 58. The calculation unit 56 reads the value of the scanning pitch corresponding to the desired value of the parameter Δy from this data and generates a new scanning pitch as change information.

[0178] The following describes a case where the parameter Δz is changed based on the state of the detection target area determined by the detection unit 54. When the parameter Δz is increased, that is, when the value of the energy density ED or temperature distribution T(r) is decreased, the calculation unit 56 generates change information so that, for example, at least one of the following changes to the molding conditions is made. In this case, the changes to the molding conditions include decreasing the pressure applied by the blade 221 to the powder material P to increase the layer thickness, increasing the particle size and particle size distribution to increase the particle size variation, and increasing the thickness of the slice model data, which is the shape data of the solidified layer. This makes it more difficult for heat from the laser beam irradiation to be transferred to the powder material P. When the parameter Δz is decreased, that is, when the value of the energy density ED or temperature distribution T(r) is increased, the calculation unit 56 generates change information so that, for example, at least one of the following changes to the molding conditions is made. In this case, the changes to the molding conditions include increasing the pressure applied by the blade 221 to the powder material P to decrease the layer thickness, decreasing the particle size and particle size distribution to reduce the particle size variation, and decreasing the thickness of the slice model data. This makes it easier for the heat generated by the laser beam irradiation to be transferred to the powder material P.

[0179] If change information is generated to change the pressure applied by the blade 221 to the powder material P, the output unit 55 outputs the generated change information as status information to the material control unit 51 of the setting unit 59. The material control unit 51, for example, controls the pressing mechanism of the blade 221 to cause the blade 221 to apply pressure to the powder material P based on the change information. If change information is generated to change the particle size and particle size distribution, the output unit 55 outputs the generated change information as status information to the material control unit 51 and the molding control unit 52 of the setting unit 59. The material control unit 51 and the molding control unit 52, for example, control the recoater 22, the drive mechanism 212, and the drive mechanism 312 to perform operations to remove the formed material layer and form a new material layer.

[0180] If change information is generated to modify the slice model data, which is the shape data of the solidified layer, the output unit 55 outputs the generated change information as status information to the molding control unit 52 of the setting unit 59. The molding control unit 52 changes the values ​​of the molding conditions for the irradiation unit 32 to emit laser light, the values ​​of the molding conditions for the scanning unit 33 to scan the laser light, and the amount of movement of the drive mechanism 312 so that a solidified layer with a new thickness based on the change information can be fabricated. In this case, data relating the thickness of the solidified layer to be fabricated, the values ​​of the molding conditions for the irradiation unit 32 to emit laser light, and the molding conditions for the scanning unit 33 to scan the laser light is stored in the storage unit 58. The molding control unit 52 refers to this data and operates the irradiation unit 32 and the scanning unit 33 with molding conditions suitable for the new solidified layer thickness.

[0181] Data relating the parameter Δz, the pressure applied to the powder material P, the particle size / particle size distribution, and the thickness of the slice model data is pre-stored in the storage unit 58. The calculation unit 56 reads the values ​​of each molding condition corresponding to the desired value of the parameter Δz from this data and generates the read-out new value as change information. Furthermore, the parameter Δz is also affected by the movement speed of the blade 221, the type (shape and material) of the blade 221, the moisture absorption of the powder material P, and the type of powder material P, so the calculation unit 56 may generate change information for each of the above. Furthermore, since Δz can also be changed by changing the amount of movement of the base plate 311 in the Z direction, the calculation unit 56 may generate change information based on the amount of drive of the drive mechanism 312 for moving the base plate 311.

[0182] The following describes the cases in which the parameters ρ, k, and α are changed based on the state of the detection target area determined by the detection unit 54. When the parameters ρ, k, and α are increased, that is, when the values ​​of energy density ED and temperature distribution T(r) are increased, the calculation unit 56 generates change information so that, for example, at least one of the following changes to the molding conditions is made. In this case, the changes to the molding conditions include increasing the pressure applied by the blade 221 to the powder material P and decreasing the particle size and particle size distribution to reduce the variation in particle size. As a result, the density of the powder material P increases, and the thermal conductivity and thermal diffusivity of the powder material P increase. As a result, heat from the irradiation of laser light is more easily conducted through the material layer. When the parameters ρ, k, and α are decreased, that is, when the values ​​of energy density ED and temperature distribution T(r) are decreased, the calculation unit 56 generates change information so that, for example, at least one of the following changes to the molding conditions is made. In this case, the changes to the molding conditions include decreasing the pressure applied by the blade 221 to the powder material P and increasing the particle size and particle size distribution to increase the variation in particle size. This reduces the density of the powder material P, and consequently, the thermal conductivity and thermal diffusivity of the powder material P decrease. As a result, heat from laser irradiation is less likely to be conducted through the material layer.

[0183] Data relating the parameters ρ, k, and α to the pressure applied to the powder material P and the particle size / particle size distribution is pre-stored in the storage unit 58. The calculation unit 56 reads the values ​​of each molding condition corresponding to the desired values ​​for each parameter from this data and generates the read-out new values ​​as change information. Furthermore, since the parameters ρ, k, and α are also affected by the movement speed of the blade 221, the type of blade 221 (shape and material), and the type of powder material P, the calculation unit 56 may generate change information for each of the above. Furthermore, parameters k and α are also affected by the moisture absorption of the powder material P. When parameters k and α are increased, that is, when the value of the temperature distribution T(r) is increased, the calculation unit 56 decreases the moisture absorption.

[0184] As described above, when the calculation unit 56 generates change information, the output unit 55 outputs the generated change information as state information to the material control unit 51, the molding control unit 52, and the housing control unit 53 of the setting unit 59, according to the content of the molding conditions to be changed. The material control unit 51 controls, for example, the operation of the material layer forming unit 20, i.e., the operation of the drive mechanism 212 that drives the bottom surface 211 of the material supply tank 21, the operation of the blade 221 (the moving speed of the blade 221, the pressure that the blade 221 applies to the powder material P, and the waiting time of the blade 221), and the heating temperature of the heater 213 that heats the powder material contained in the material supply tank 21. Also, for example, the molding control unit 52 controls the operation of the irradiation unit 32, the scanning unit 33, the base plate 311, and the drive mechanism 312 that drives the heater 313 according to the content of the change information, and modifies the design data. Furthermore, for example, the housing control unit 53 controls the operation of the heater 15, the intake device 131, and the exhaust device 14 according to the change information, thereby controlling the atmosphere inside the housing 10. The calculation unit 56 may also use a correction value, which is the difference between the newly generated values ​​for each molding condition and the current values ​​for the molding conditions, as change information. In this case, the output unit 55 outputs the change information generated by the calculation unit 56 as status information to the setting unit 59. The material control unit 51, molding control unit 52, and housing control unit 53 use the input status information as a correction value to correct the molding conditions and control the operation of each unit.

[0185] Next, we will explain one specific example of the processing performed by the detection unit 54 and the calculation unit 56, specifically in the case of real-time modification and the case of modification during the next layer fabrication. First, let's explain one specific example of the processing when real-time changes are made. In the following explanation, we will give examples of when the detection unit 54 determines the state of the powder material P before heating and when it determines the state of the melted material as the state of the detection target area. First, as an example of processing during real-time changes, the detection unit 54 obtains information regarding the temperature of the powder material P (i.e., the vicinity of the molten pool MP) that has not yet begun to melt before being heated by laser irradiation, and the calculation unit 56 generates change information to maintain the energy density ED within a desired range. Note that the calculation unit 56 is not limited to generating change information to maintain the energy density ED within a desired range, but may generate change information to maintain at least one of the power density PD, energy density ED, and temperature distribution T(r) within a desired range.

[0186] Each process in the flowchart shown in Figure 10 is stored in the memory unit 58 of the arithmetic unit 50, read by the arithmetic unit 50, and executed. In step S31, the material control unit 51 causes the material layer formation unit 20 to form a material layer according to the set molding conditions and proceeds to step S32. In step S32, the molding control unit 52 causes the molding unit 30 to form a solidified layer according to the set molding conditions. When the irradiation of laser light by the irradiation unit 32 is started, the calculation unit 50 causes the imaging device 41 to image the detection target area on the surface of the material layer. The detection unit 54 generates temperature image data based on the image data generated by the imaging device 41 and determines the temperature of the powder material P in the material layer before melting from the temperature image data. The detection unit 54 may also determine the temperature of the solidification region BE adjacent to the path through which the laser light is scanned.

[0187] In step S33, the determination unit 57 determines whether the temperature of the powder material P in the material layer, as determined by the detection unit 54, meets a predetermined first reference range. The first reference range is the temperature range of the material layer (powder material P) for which the energy density ED is maintained within the desired range described above. This first reference range (temperature range of the powder material P) is set based on the correlation between the temperature of the powder material P and the energy density ED, for example, determined by various tests or simulations performed by the user. This first reference range is stored in the storage unit 58 in advance, and the determination unit 57 reads this first reference range and uses it for the determination process in step S33 and step S34 described later.

[0188] The first reference temperature range can be, for example, 20°C ± 5°C at room temperature and 200°C ± 10°C when preheating is performed, if the powder material P is aluminum. If the determination unit 57 determines that the temperature of the material layer does not meet the first reference range, the process proceeds to step S34. If the determination unit 57 determines that the temperature of the material layer meets the first reference range, the process proceeds to step S37, which will be described later. In other words, in step S33, the determination unit 57 determines whether or not it is necessary to generate change information. Furthermore, the first reference range described above is not limited to energy density ED, but may be set so that power density PD or temperature distribution T(r) is kept within a desired range.

[0189] In step S34, the determination unit 57 determines whether the temperature of the material layer is higher than or lower than the first reference range. If the determination unit 57 determines that the temperature of the material layer is higher than the first reference range, the process proceeds to step S35. If the determination unit 57 determines that the temperature of the material layer is lower than the first reference range, the process proceeds to step S36. Furthermore, if the detection unit 54 determines the temperature of an adjacent solidification region BE, the determination unit 57 compares it with a first reference range, which is set as the temperature range of the material layer in which at least one of the energy density ED, power density PD, and temperature distribution T(r) is kept within a desired range when affected by the heat of the adjacent solidification region BE.

[0190] In step S35, the calculation unit 56 generates modification information to change the molding conditions so as to lower the value of the energy density ED in order to bring the energy density ED within the desired range. The reason for lowering the energy density ED is as follows: Because the temperature of the material layer is higher than the first reference range, when the powder material P is irradiated with laser light, the temperature of the powder material P rises to the desired temperature (e.g., the melting point) even with a small amount of heat. For this reason, it is predicted that the energy density ED of the energy absorbed by the powder material P will be excessive. To lower the energy density ED and reduce the energy absorbed by the powder material P, it is possible to reduce the output of the laser beam from the irradiation unit 32, thereby reducing the energy absorbed by the powder material P. Alternatively, it is possible to reduce the heating effect of the powder material P due to laser irradiation by increasing the flow rate of the inert gas and increasing the flow velocity of the inert gas to cool the surface of the material layer and lower the temperature of the powder material P. Furthermore, it is possible to reduce the energy absorbed by the powder material P by increasing the scanning speed of the laser beam by the scanning unit 33, thereby shortening the time that the laser beam irradiates the same position on the material layer.

[0191] Based on the above reasoning, the calculation unit 56 reduces the value of the energy density ED by, for example, parameter P L The arithmetic unit 56 generates change information so that at least one of the following changes to the molding conditions is made: parameter P LThe modification related to parameter P0 is to lower the laser power. The modification related to parameter v is to increase the flow rate and velocity of the inert gas. The modification related to parameter v is to increase the scanning speed.

[0192] In this case, the calculation unit 56 calculates the amount by which the energy density ED is reduced (decrease amount) based on the difference between the temperature of the material layer determined by the detection unit 54 and an arbitrary value within the first reference range (e.g., maximum value or median value). In this case, the data relating the decrease in energy density ED and the difference between the temperature of the material layer and an arbitrary value within the first reference range (e.g., maximum value or median value) is stored in the storage unit 58 in advance, and the calculation unit 56 calculates the decrease in energy density ED by referring to this data. Based on the decrease in energy density ED, the calculation unit 56 calculates each parameter P from equation (2). L The calculation unit 56 calculates new values ​​for P0 and v. The calculation unit 56 refers to data stored in the storage unit 58 beforehand, which associates the values ​​of each parameter with the values ​​of each molding condition, and calculates the values ​​of each molding condition corresponding to the newly calculated parameter values, and generates the values ​​of those molding conditions as change information. As described above, the calculation unit 56 may also generate a correction value, which is the difference between the new molding condition values ​​and the current molding condition values, as change information, and the output unit 55 may output this correction value as status information to the setting unit 59.

[0193] The output unit 55 outputs the change information generated by the calculation unit 56 as status information to the setting unit 59 (at least one of the molding control unit 52 and the housing control unit 53). If the molding control unit 52 receives change information, the molding control unit 52 causes at least one of the irradiation unit 32 and the scanning unit 33 to perform at least one of the following operations. In this case, the operation of the irradiation unit 32 is to emit laser light with a new laser output based on the change information. The operation of the scanning unit 33 is to drive the galvanometer mirrors 331 and 332 at a new tilt angle change speed based on the change information. If the housing control unit 53 receives change information, the housing control unit 53 operates the intake device 131 and exhaust device 14 with new valve openings and exhaust volumes based on the change information. After that, the process returns to step S32.

[0194] In step S36, the calculation unit 56 generates modification information to change the molding conditions so as to increase the energy density ED. The reason for increasing the energy density ED is as follows: Because the temperature of the material layer is lower than the first reference range, when the powder material P is irradiated with laser light, a large amount of heat is required for the temperature of the powder material P to rise to the desired temperature (e.g., melting point). Therefore, it is predicted that the energy density ED of the energy absorbed by the powder material P will be insufficient.

[0195] In this case, the calculation unit 56 changes the molding conditions to increase the value of the energy density ED, based on the opposite approach to the one described in step S35 above. In this case, the calculation unit 56 uses parameter P L The calculation unit 56 generates change information so that at least one of the following changes to the molding conditions is made: parameter P LA change in the molding conditions related to parameter P0 is to increase the laser power. A change in the molding conditions related to parameter v is to decrease the flow rate and flow velocity of the inert gas. A change in the molding conditions related to parameter v is to decrease the scanning speed. The calculation unit 56 calculates the amount to increase the energy density ED value (increase amount) based on the difference between the temperature of the material layer determined by the detection unit 54 and an arbitrary value in the first reference range (e.g., minimum or median). In this case as well, the increase amount and the data relating the difference between the temperature of the material layer and an arbitrary value in the first reference range (e.g., minimum or median) are stored in the storage unit 58 in advance, and the calculation unit 56 calculates the increase amount of the energy density ED value by referring to this data. Based on the increase amount of the energy density ED, the calculation unit 56 calculates each parameter P L The calculation unit 56 calculates new values ​​for P0 and v. The calculation unit 56 refers to data stored in the storage unit 58 beforehand, which associates the values ​​of each parameter with the values ​​of each molding condition, and calculates the values ​​of each molding condition corresponding to the newly calculated parameter values, and generates the values ​​of those molding conditions as change information.

[0196] The output unit 55 outputs the change information as status information to the setting unit 59 (at least one of the molding control unit 52 and the housing control unit 53). If the molding control unit 52 receives change information, the molding control unit 52 causes at least one of the irradiation unit 32 and the scanning unit 33 to perform at least one of the following operations. In this case, the operation of the irradiation unit 32 is to emit laser light with a new laser output based on the change information. The operation of the scanning unit 33 is to drive the galvanometer mirrors 331 and 332 at a new tilt angle change speed based on the change information. If the housing control unit 53 receives change information, the housing control unit 53 operates the intake device 131 and exhaust device 14 with new valve openings and exhaust volumes based on the change information. After that, the process returns to step S32. In this case as well, the calculation unit 56 may generate a correction value, which is the difference between the new molding condition value and the current molding condition value, as change information, and the output unit 55 may output this correction value as status information to the setting unit 59.

[0197] In step S37, which proceeds when the temperature of the material layer meets the first reference range, the calculation unit 50 determines whether the fabrication of one solidified layer is complete. If the fabrication of one solidified layer is not complete, the calculation unit 50 negates step S37, and the process returns to step S32. If the fabrication of one solidified layer is complete, the calculation unit 50 affirms step S37, and the process proceeds to step S38. In step S38, the calculation unit 50 determines whether the fabrication of all solidified layers is complete. If the processing of all solidified layers is not complete, the calculation unit 50 negates step S38, and the process proceeds to step S31. If the processing of all solidified layers is complete, the calculation unit 50 affirms step S38, and all processes are terminated.

[0198] In the above explanation, the detection unit 54 used the example of determining the temperature of the powder material P before it is heated by laser irradiation, but it is not limited to this example. For example, foreign matter and sputtering SP mixed in the powder material P of the material layer may be detected. In this case, the detection unit 54 may detect foreign matter and sputtering SP from the image data captured by the imaging device 41 using a known image processing method, without obtaining temperature information using the two-color method. In this case, the detection unit 54 may, for example, use a previously acquired training image to separate and detect the powder material P, foreign matter, and sputtering SP from the image data captured by the imaging device 41 based on the differences in size and shape of the powder material P particles, foreign matter, and sputtering SP. Alternatively, foreign matter and sputtering SP may be detected on a color image captured and generated by an imaging device different from the imaging device 41. By performing the above process, the energy density ED, which is one of the basic conditions for the melting and solidification of the powder material P, can be maintained within the desired range, thereby suppressing the occurrence of defects in the solidified layer due to insufficient or excessive energy in the powder material P.

[0199] Next, as an example of a specific example of processing when making real-time changes, we will give an example in which the detection unit 54 obtains information on the temperature of the molten pool MP and its vicinity as the molten state, and the calculation unit 56 generates change information so as to keep the value of the energy density ED within a desired range. Note that the calculation unit 56 is not limited to generating change information so as to keep the value of the energy density ED within a desired range, but may generate change information so as to keep at least one of the power density PD value, the energy density ED value, and the temperature distribution T(r) value within a desired range.

[0200] Each process in the flowchart shown in Figure 11 is stored in the memory unit 58 of the arithmetic unit 50, read by the arithmetic unit 50, and executed. The processes in steps S41 and S42 are the same as those in steps S31 and S32 shown in the flowchart of Figure 10. However, in step S42, the detection unit 54 uses the temperature image data generated from the image data captured by the imaging device 41 to determine the temperature distribution of the molten pool MP as information about the temperature of the molten pool MP and its vicinity. In the specific example shown in Figure 11, the detection unit 54 determines the diameter of an isotherm at an arbitrary temperature in the molten pool MP from the temperature image data.

[0201] In step S43, the determination unit 57 determines whether the temperature distribution of the molten pool MP, i.e., the diameter of the isotherm at any temperature in the molten pool MP, as determined by the detection unit 54, satisfies a predetermined first reference range. The first reference range is the range of isotherm diameters for which the temperature distribution T(r) is kept within a desired range. This first reference range is set based on the correlation between the temperature distribution of the molten pool MP (the diameter of the isotherm at any temperature) and the temperature distribution T(r), which is determined, for example, by various tests and simulations performed by the user. This first reference range is stored in the storage unit 58 in advance, and the determination unit 57 reads this first reference range and uses it for the determination process in step S43 and step S44 described later. If the determination unit 57 determines that the diameter of the isotherm of the molten pool MP does not satisfy the first reference range, the process proceeds to step S44. If the determination unit 57 determines that the diameter of the isotherm satisfies the first reference range, the process proceeds to step S47 described later. In other words, the determination unit 57 determines in step S43 whether or not it is necessary to generate change information. Furthermore, the first reference range described above is not limited to the temperature distribution T(r), but may be set so that the power density PD and energy density ED are kept within a desired range. Also, the range of isotherm diameters that constitute the first reference range may be the range of isotherm diameters corresponding to the temperature range from between the melting point and the liquidus temperature of the powder material P used to between the melting point and the solidus temperature.

[0202] In step S44, the determination unit 57 determines whether the diameter of the isotherm is higher than or lower than the first reference range. If the determination unit 57 determines that the diameter of the isotherm is higher than the first reference range, the process proceeds to step S45. If the determination unit 57 determines that the diameter of the isotherm is lower than the first reference range, the process proceeds to step S46.

[0203] In step S45, the calculation unit 56 generates modification information to change the molding conditions so as to reduce the value of the energy density ED in order to bring the value of the energy density ED into the desired range. The reason for reducing the value of the energy density ED is as follows: If the diameter of the isotherm of the molten pool MP is larger than the first reference range, it means that the molten pool MP is larger than the molten pool MP that is expected to be obtained under the currently set molding conditions. This allows us to estimate that the energy density ED of the energy absorbed by the powder material P inside the material layer is excessive.

[0204] In this case, the calculation unit 56 reduces the value of the energy density ED by adjusting the parameter P, similar to the case of step S35 in Figure 10. L The calculation unit 56 generates change information so that at least one of the following is performed: lowering P0 and increasing parameter v. That is, the calculation unit 56 generates change information so that at least one of the following is performed: lowering the laser output, increasing the flow rate and velocity of the inert gas, and lowering the scanning speed. The specific processing that the calculation unit 56 performs to generate the change information is done in the same way as in step S35 described in Figure 10, by referring to the data stored in the storage unit 58. The output unit 55 outputs the change information generated by the calculation unit 56 as state information to the setting unit 59 (at least one of the molding control unit 52 and the housing control unit 53). When the molding control unit 52 receives change information, the molding control unit 52 causes at least one of the following operations to be performed by at least one of the irradiation unit 32 and the scanning unit 33. In this case, the operation of the irradiation unit 32 is to emit laser light with a new laser output based on the change information. The operation of the scanning unit 33 is to drive the galvanometer mirrors 331 and 332 at a new tilt angle change speed based on the change information. When the housing control unit 53 receives change information, the housing control unit 53 operates the intake device 131 and exhaust device 14 with new valve openings and exhaust volumes based on the change information. After that, the process returns to step S42.

[0205] In step S46, the calculation unit 56 generates modification information to change the molding conditions so that the value of the energy density ED is increased in order to bring the value of the energy density ED into the desired range. The reason for increasing the energy density ED is as follows: If the diameter of the isotherm in the molten pool MP is smaller than the first reference range, it means that the molten pool MP is smaller than the molten pool MP that is expected to be obtained under the currently set molding conditions. This allows us to estimate that the energy density ED of the energy absorbed by the powder material P inside the material layer is insufficient.

[0206] In this case, the calculation unit 56 increases the energy density ED by adjusting the parameter P, similar to the case of step S36 in Figure 10. L The calculation unit 56 generates change information so that at least one of the following is performed: increasing P0 and decreasing parameter v. That is, the calculation unit 56 generates change information so that at least one of the following is performed: increasing the laser output, decreasing the flow rate and flow velocity of the inert gas, and decreasing the scanning speed. The specific processing that the calculation unit 56 performs to generate the change information is done in the same way as in step S36 described in Figure 10, by referring to the data stored in the storage unit 58. The output unit 55 outputs the change information generated by the calculation unit 56 as state information to the setting unit 59 (at least one of the molding control unit 52 and the housing control unit 53). When the molding control unit 52 receives change information, the molding control unit 52 causes at least one of the following operations to be performed by at least one of the irradiation unit 32 and the scanning unit 33. In this case, the operation of the irradiation unit 32 is to emit laser light with a new laser output based on the change information. The operation of the scanning unit 33 is to drive the galvanometer mirrors 331 and 332 at a new tilt angle change speed based on the change information. When the housing control unit 53 receives change information, it operates the intake device 131 and exhaust device 14 with new valve openings and exhaust volumes based on the change information. The process then returns to step S42. In steps S45 and S46, the arithmetic unit 56 may generate a correction value, which is the difference between the value of the new shaping condition and the value of the current shaping condition, as change information, and the output unit 55 may output this correction value as state information to the setting unit 59.

[0207] The processing of steps S47 and S48, which proceed when the diameter of the isotherm satisfies the first reference range, is the same as the processing of steps S37 and S38 in FIG. 10. By performing the above processing, the basic conditions when the powder material P melts and solidifies are maintained within a desired range, and the occurrence of defective shaping of the solidified layer due to insufficient melting or excessive melting can be suppressed. In step S42, the detection unit 54 may obtain the ratio of the major axis to the minor axis on the XY plane of the melting pool MP and the temperature gradient of the melting pool MP on the XY plane as information regarding the temperature of the melting pool MP and its vicinity. Also in this case, the ratio of the major axis to the minor axis on the XY plane of the melting pool MP and the temperature gradient of the melting pool MP on the XY plane for maintaining at least one of the energy density ED, the power density PD, and the temperature distribution T(r) within a desired range may be used as the first reference range. Also in this case, the first reference range is set based on the results of various tests and simulations by the user, as described above.

[0208] When the ratio of the major axis to the minor axis of the melting pool MP is larger than the first reference range, it can be estimated that the energy density ED of the energy absorbed by the powder material P is excessive and the melting pool MP is larger than the melting pool MP assumed from the currently set shaping conditions. Therefore, the arithmetic unit 56 may generate change information in the same manner as in step S45 so that the value of the energy density ED decreases. When the ratio of the major axis to the minor axis of the melting pool MP is smaller than the first reference range, the arithmetic unit 56 may generate change information in the same manner as in step S46 based on the reverse idea. Also, when the temperature gradient of the melting pool MP is greater than the first reference range, it can be estimated that the energy density ED of the energy absorbed by the powder material P becomes excessive, and the temperature change in the melting pool MP becomes intense. Therefore, the calculation unit 56 may generate change information in the same manner as in step S45 so that the value of the energy density ED decreases. When the temperature gradient of the melting pool MP is smaller than the first reference range, based on the reverse idea, the calculation unit 56 may generate change information in the same manner as in step S46.

[0209] Next, as an example of a specific example of the process when performing real-time change, an example is given where the detection unit 54 obtains the state of the sputter SP, and the calculation unit 56 generates change information so as to keep the value of the energy density ED within a desired range. Note that the calculation unit 56 is not limited to generating change information so as to keep the value of the energy density ED within a desired range, and may generate change information so as to keep at least one of the value of the power density PD, the value of the energy density ED, and the value of the temperature distribution T(r) within a desired range.

[0210] Each process of the flowchart shown in FIG. 12 is stored in the storage unit 58 of the arithmetic device 50, read by the arithmetic device 50, and executed. The processes of steps S51 and S52 are the same as the processes of steps S31 and S32 shown in the flowchart of FIG. 10. However, in step S52, the detection unit 54 obtains the state of the sputter SP from the temperature image data by using the method described with reference to FIG. 6, using the temperature image data generated from the image data generated by the imaging of the imaging device 41. In the specific example shown in the flowchart of FIG. 12, an example is given where the detection unit 54 obtains the scattering amount of the sputter SP as the state of the sputter SP.

[0211] In step S53, the determination unit 57 determines whether the state of the sputtered SP, i.e., the amount of sputtered SP, determined by the detection unit 54, satisfies a first reference range. The first reference range is the range of sputtered SP scattering amounts required to maintain the energy density ED within a desired range. This range of sputtered SP scattering amounts is set based on the correlation between the amount of sputtered SP scattering and the energy density ED, for example, determined by various tests and simulations performed by the user. This range of sputtered SP scattering amounts (first reference range) is stored in advance in the storage unit 58, and the determination unit 57 reads this first reference range and uses it for the determination process in step S53 and step S54 described later. If the determination unit 57 determines that the amount of sputtered SP scattering does not satisfy the first reference range, the process proceeds to step S54. If the determination unit 57 determines that the amount of sputtered SP scattering satisfies the first reference range, the process proceeds to step S57 described later. In other words, the determination unit 57 determines in step S53 whether or not it is necessary to generate change information. Furthermore, the first reference range described above is not limited to energy density ED, but may be set so that power density PD or temperature distribution T(r) is kept within a desired range.

[0212] In step S54, the determination unit 57 determines whether the amount of sputtered SP is greater than or less than the first reference range. If the determination unit 57 determines that the amount of sputtered SP is greater than the first reference range, the process proceeds to step S55. If the determination unit 57 determines that the amount of sputtered SP is less than the first reference range, the process proceeds to step S56.

[0213] In step S55, the calculation unit 56 generates modification information to change the molding conditions so as to lower the value of the energy density ED in order to bring the value of the energy density ED within the desired range. The reason for lowering the value of the energy density ED is as follows: If the amount of sputtering SP is greater than the first reference range, it means that the amount of heat applied to the powder material P is excessive and the convection C of the molten pool MP is large. In other words, it can be estimated that the energy density ED of the energy absorbed by the powder material P is excessive.

[0214] In this case, the calculation unit 56 reduces the value of the energy density ED by adjusting the parameter P, similar to the case of step S35 in Figure 10 and step S45 in Figure 11. L The calculation unit 56 generates change information so that at least one of the following is performed: lowering P0 and increasing parameter v. That is, the calculation unit 56 generates change information so that at least one of the following is performed: lowering the laser output, increasing the flow rate and velocity of the inert gas, and increasing the scanning speed. The specific processing that the calculation unit 56 performs to generate the change information is done in the same way as described in Figure 10, by referring to the data stored in the storage unit 58. The output unit 55 outputs the change information generated by the calculation unit 56 as state information to the setting unit 59 (at least one of the molding control unit 52 and the housing control unit 53). When the molding control unit 52 receives change information, the molding control unit 52 performs at least one of the following: the irradiation unit 32 emits laser light with a new laser output based on the change information, and the scanning unit 33 drives the galvanometer mirrors 331 and 332 with a new tilt angle change speed based on the change information. When the housing control unit 53 receives change information, it operates the intake device 131 and exhaust device 14 with new valve openings and exhaust volumes based on the change information. The process then returns to step S52.

[0215] In step S56, the calculation unit generates modification information to change the molding conditions so that the value of the energy density ED is increased in order to bring the value of the energy density ED into the desired range. The reason for increasing the value of the energy density ED is as follows: If the amount of sputtering SP is less than the first reference range, it means that the amount of heat applied to the powder material P is insufficient and the convection C of the molten pool MP is small. In other words, it can be inferred that the energy density ED of the energy absorbed by the powder material P is insufficient.

[0216] In this case, the calculation unit 56 increases the value of the energy density ED by adjusting the parameter P, similar to the case of step S36 in Figure 10 and step S46 in Figure 11. L The calculation unit 56 generates change information so that at least one of the following is performed: increasing P0 and decreasing parameter v. That is, the calculation unit 56 generates change information so that at least one of the following is performed: increasing the laser output, decreasing the flow rate and velocity of the inert gas, and decreasing the scanning speed. The specific processing that the calculation unit 56 performs to generate change information is carried out by referring to the data stored in the storage unit 58, as described in Figure 10.

[0217] The output unit 55 outputs the change information generated by the calculation unit 56 as status information to at least one of the molding control unit 52 and the housing control unit 53. If the molding control unit 52 receives change information, the molding control unit 52 causes at least one of the irradiation unit 32 and the scanning unit 33 to perform at least one of the following operations. In this case, the operation of the irradiation unit 32 is to emit laser light with a new laser output based on the change information. The operation of the scanning unit 33 is to drive the galvanometer mirrors 331 and 332 at a new tilt angle change speed based on the change information. If the housing control unit 53 receives change information, the housing control unit 53 operates the intake device 131 and exhaust device 14 with new valve openings and exhaust volumes based on the change information. After that, the process returns to step S52. In steps S55 and S56, the calculation unit 56 generates a correction value as change information, which is the difference between the new molding condition value and the current molding condition value, and the output unit 55 may output this correction value as status information to the setting unit 59.

[0218] The processes in steps S57 and S58, which proceed when the amount of sputter scattering meets the first reference range, are the same as the processes in steps S37 and S38 in Figure 10. By performing the above process, the state inside the molten pool MP is controlled, thereby reducing the occurrence of internal defects in the solidified layer formed by the solidification of the molten pool MP.

[0219] In step S52, the detection unit 54 may determine the scattering direction and scattering velocity of the sputtered SP as the state of the sputtered SP using the method described with reference to Figure 6. When the detection unit 54 determines the scattering direction of the sputtered SP, the first reference range is the range of the sputtered SP scattering direction in which at least one of the power density PD, energy density ED, and temperature distribution T(r) is kept within the desired range. This range of the sputtered SP scattering direction (first reference range) is set based on the results of various tests and simulations performed by the user, for example, as in step S53 described above. The determination unit 57 determines that the first reference range is not met if the scattering direction of the sputtered SP around the keyhole KH is not fixed in a certain direction (for example, backward relative to the scanning direction of the laser beam) but is irregularly varied. As described above, if the scattering direction of the sputtered SP is not fixed in a certain direction, it means that the powder material P is receiving excessive energy. This means that the keyhole KH is getting deeper and the convection C in the molten pool MP is getting more intense, so the calculation unit 56 generates modification information to reduce the value of the energy density ED.

[0220] When the detection unit 54 determines the scattering velocity of the sputtered SP, the first reference range is the range of sputtered SP scattering velocities for which at least one of the power density PD, energy density ED, and temperature distribution T(r) is kept within the desired range. This range of sputtered SP scattering velocities (first reference range) is set based on the results of various tests and simulations performed by the user, for example, as in step S53 described above. The determination unit 57 determines that the first reference range is not met if the scattering velocity is high. As described above, a high sputtered SP scattering velocity means that the convection C of the molten pool MP is intense, so the calculation unit 56 generates modification information to reduce the value of the energy density ED.

[0221] The detection unit 54 may also determine the state of the fume FU as the state of the area to be detected. The detection unit 54 will now explain how to determine the concentration of fume FU as the state of fume FU using the method described with reference to Figure 7. In this case, the first reference range is the range of fume FU concentration for which at least one of the power density PD, energy density ED, and temperature distribution T(r) is kept within the desired range. This range of fume FU concentration (first reference range) is set based on the results of various tests and simulations performed by the user, for example, as in steps S33, S43, and S53 described above. The determination unit 57 determines that the higher the concentration, the less the first reference range is met. As described above, the higher the concentration of fume FU, the more fume FU is generated, meaning that the temperature in the molten pool MP is too high because the powder material P is absorbing too much energy. Therefore, the calculation unit 56 generates modification information to reduce the value of the energy density ED.

[0222] The detection unit 54 will now explain how to determine the range of the fume FU as the state of the fume FU using the method described with reference to Figure 7. In this case, the first reference range is the range of the fume FU in which at least one of the power density PD, energy density ED, and temperature distribution T(r) is kept within the desired range. This range of the fume FU (first reference range) is set based on the results of various tests and simulations performed by the user, for example, as in step S53 described above. The determination unit 57 determines that the first reference range is not met if the range of the fume FU, i.e., the area on the temperature image, is large. As described above, a wide range of fume FU means that the amount of fume FU generated is large, the amount of energy absorbed by the powder material P is excessive, and the temperature in the molten pool MP is too high. For this reason, the calculation unit 56 generates modification information to reduce the value of the energy density ED.

[0223] Furthermore, in steps S35, S36, S45, S46, S55, and S56 of the flowchart shown in Figures 10, 11, and 12 above, the calculation unit 56 performs the calculation of parameter P L Which of the parameters P0 and v to change or not change depends on the user's requirements for the fabrication of the three-dimensional object. For example, if the user wants to avoid an increase in fabrication time, in steps S36, S46, and S56 above, the calculation unit 56 will adjust the parameter P L The value of can be changed without changing the value of parameter v. For example, if the energy density ED is lower than the desired range, the calculation unit 56 will not change the value of parameter v, and the calculation unit 56 will change parameter P L The system generates change information to increase the value of [variable name]. In this case, the printing time is maintained, but the temperature change during the solidification process of the powder material P melted by the laser irradiation becomes larger, which increases the residual stress in the solidified layer and may reduce the quality of the three-dimensional object that is printed.

[0224] On the other hand, if the user wishes to avoid a decrease in the quality of the three-dimensional object being fabricated, in steps S36, S46, and S56 above, the calculation unit 56 changes the value of parameter v so that the laser beam output does not increase, thereby changing the value of parameter P L The value of can be kept unchanged. For example, if the energy density ED is lower than the desired range, the calculation unit 56 will change the parameter P L The system generates change information to decrease the value of parameter v without increasing the value of . In this case, the residual stress in the solidified layer due to temperature changes does not increase, and the quality of the fabricated 3D object is maintained, although the fabrication time may increase.

[0225] As described above, there are multiple types of parameters that can be changed in order to maintain the energy density ED within a desired range, so the parameters to be changed by the calculation unit 56 may be determined based on the user's instructions. In this case, the calculation unit 56 will inform the user of information to accept the user's predetermined specifications (hereinafter referred to as specified information) in order to determine the parameters to be changed. For example, the calculation unit 56 may determine the parameters that can be changed in order to maintain the energy density ED within a desired range (for example, parameter v and parameter P L The specified target information may be displayed on a display device, such as a liquid crystal display, which is configured to communicate with the calculation unit 56. The user then uses a specifying device, such as a mouse, which is not shown, to specify the parameter displayed on the display device (for example, parameter v). The calculation unit 56 generates change information to modify the value of the parameter specified by the user (for example, parameter v) so that the energy density ED is maintained within the desired range.

[0226] For the sake of explanation, the parameters v and P are described based on the flowcharts shown in Figures 10 to 12. L Although the example shows two types of parameters as specified target information and displaying them on a display device (not shown), the parameters to be displayed on the display device as specified target information are parameter v and parameter P LIt is not limited to these two types of parameters. For example, the arithmetic unit 56 uses parameter v and parameter P L Among the other parameters P0, η, d, Δy, Δz, ρ, k, r, x, α, T0 mentioned above, which are different from the above, several parameters that can be changed in order to maintain the basic conditions and detailed conditions (described later) within a desired range may be displayed on the display device as specified target information. When at least one of the displayed multiple parameters is specified by the user, the calculation unit 56 generates change information that modifies the value of the parameter specified by the user so that the basic conditions and detailed conditions (described later) are maintained within a desired range.

[0227] Furthermore, the specified target information that the calculation unit 56 displays on the display device (not shown) is not limited to parameters. For example, the calculation unit 56 may display multiple molding conditions that can be changed in order to maintain the basic conditions and detailed conditions (described later) within a desired range as specified target information on the display device. Furthermore, since the changing parameters and molding conditions affect the molding time and quality of the three-dimensional object, the user is not limited to specifying the parameters and molding conditions to be changed as described above. Instead, the user may choose to prioritize (maintain) the molding time of the three-dimensional object or prioritize (maintain) the quality of the three-dimensional object. In this case, as an example, the calculation unit 56 displays items related to time emphasis and quality emphasis as specified target information on a display device (not shown). The user uses a specification device (not shown), such as a mouse, to specify one of the items related to time emphasis or quality emphasis displayed on the display device. The calculation unit 56 generates change information that changes the values ​​of the parameters and molding conditions according to the items specified by the user so that the basic conditions and detailed conditions (described later) are maintained within the desired range. For example, if the energy density ED is lower than the desired range, and the user specifies an item related to time emphasis, the calculation unit 56 will not change the value of parameter v, but will change parameter P L It generates change information to change the value of . On the other hand, if the user specifies items related to quality emphasis, the calculation unit 56 will change parameter P L The value of is not changed, but change information is generated to change the value of parameter v.

[0228] In addition to emphasizing time and quality, items related to balance emphasis that emphasize the balance between shaping time and quality may be displayed as designated target information on a display device (not shown) together with at least one of the items related to time emphasis and quality emphasis. For example, when the energy density ED is lower than the desired range, if an item related to balance emphasis is specified by the user, the calculation unit 56 L generates change information so as to change the values of both the parameter v and the parameter P. Note that the display form of each item related to time emphasis, quality emphasis, or balance emphasis on the display device may be any existing form such as a character example or an icon as long as the user can identify it. Note that the display device (not shown) does not have to be a liquid crystal display, and may be an existing display device such as an organic EL display or a head-mounted display. Also, the designation device (not shown) does not have to be a mouse, and may be an existing device such as a touch panel. Note that the method of notifying the designated target information to the user is not limited to the display of the display device. For example, using a speaker and a microphone (not shown), the calculation unit 56 may notify the designated target information to the user through the speaker (voice) and receive the designation from the user through the microphone (voice), or other existing methods may be used. Also, in steps S35, S36, S45, S46, S55, and S56, the calculation unit 56 L In addition to P, P0, and v, shaping conditions that affect the energy density ED and can be changed during real-time change may be generated. For example, the calculation unit 56 may generate change information regarding the oscillation mode of the laser light of the irradiation unit 32, the intensity distribution of the laser light, the spot size of the laser light, the scanning path of the laser light by the scanning unit 33, and the scanning pitch.

[0229] Next, an example of a specific example of the process when performing the next layer shaping time change will be described. In the following description, the detection unit 54 will be described separately for the case where the state of the molten state is obtained as the state of the detection target region and the case where the state of the sputter SP is obtained. First, as an example of the process when making changes during subsequent layer fabrication, the detection unit 54 obtains information about the molten state, specifically the temperature of the molten pool MP and its vicinity, during the fabrication of the solidified layer. Based on the temperature information obtained by the detection unit 54 during the fabrication of the solidified layer, the calculation unit 56 generates change information to maintain the value of the energy density ED within a desired range when a new solidified layer is fabricated on top of the solidified layer. Note that the calculation unit 56 is not limited to generating change information to maintain the value of the energy density ED within a desired range; it may also generate change information to maintain at least one of the power density PD, energy density ED, and temperature distribution T(r) within a desired range.

[0230] Each process in the flowcharts shown in Figures 13 and 14 is stored in the memory unit 58 of the arithmetic unit 50, read by the arithmetic unit 50, and executed. In step S61, the molding control unit 52 causes the molding unit 30 to fabricate a solidified layer under the set molding conditions. While the solidified layer is being fabricated, the calculation unit 50 causes the imaging device 41 to image the detection target area on the surface of the material layer, for example, at predetermined time intervals or each time the laser beam is scanned by the scanning unit 33 by a predetermined distance on the XY plane. The detection unit 54 generates temperature image data each time image data is output from the imaging device 41, and for each generated temperature image data, it obtains information about the temperature of the molten pool MP and its vicinity and stores it in the storage unit 58. In the specific example shown in the flowcharts of Figures 13 and 14, the detection unit 54 takes the case where it obtains the average temperature of the molten pool MP as information about the temperature of the molten pool MP and its vicinity. The detection unit 54 obtains the high-temperature region of the temperature image data that is above a first predetermined temperature as the region on the image corresponding to the molten pool MP, obtains the temperature of any point within the high-temperature region on the image, and calculates the average of the obtained temperatures to obtain the average temperature of the molten pool MP. Furthermore, the detection unit 54 generates temperature image data and stores it in the storage unit 58 during the formation of the solidified layer, and after the formation of one solidified layer is completed, the average temperature of the molten pool MP may be determined from each of the multiple temperature image data stored in the storage unit 58.

[0231] In step S62, the arithmetic unit 50 determines whether the formation of one solidified layer is complete. If the formation of one solidified layer is complete, the arithmetic unit 50 affirms step S62, and the process proceeds to step S63. If the formation of one solidified layer is not complete, the arithmetic unit 50 negates step S62, and the process returns to step S61.

[0232] In step S63, the determination unit 57 determines whether the temperature distribution of the molten pool MP, i.e., the average temperature of the molten pool MP, determined by the detection unit 54, satisfies a predetermined second reference range. The second reference range is the range of average temperatures of the molten pool MP for which the energy density ED is maintained within a desired range. This second reference range (range of average temperatures of the molten pool MP) is set based on the correlation between the average temperature of the molten pool MP and the energy density ED, for example, determined by the results of various tests and simulations performed by the user. The second reference range is stored in advance in the storage unit 58, and the determination unit 57 reads this second reference range and uses it for the determination process in step S63 and step S65 described later. If the determination unit 57 determines that the average temperature of the molten pool MP does not satisfy the second reference range, the process proceeds to step S64. If the determination unit 57 determines that the average temperature of the molten pool MP satisfies the second reference range, the process proceeds to step S71 described later. In other words, the determination unit 57 determines in step S63 whether or not it is necessary to generate change information. Furthermore, the second reference range described above is not limited to energy density ED, but may be set so that power density PD or temperature distribution T(r) is kept within a desired range. Also, the average temperature range, which is the second reference range, may be a temperature range from the temperature between the melting point and the liquidus temperature of the powder material P used to the temperature between the melting point and the solidus temperature.

[0233] In step S64, the determination unit 57 determines whether the average temperature of the molten pool MP, as determined by the detection unit 54, satisfies a third reference range. The third reference range is the range of average temperatures of the molten pool MP required to maintain the energy density ED within a desired range when the molding conditions are changed. The maximum value of the third reference range is greater than the maximum value of the second reference range, and the minimum value of the third reference range is smaller than the minimum value of the second reference range. The third reference range may also be the range between the values ​​near the maximum value and the values ​​near the minimum value. If the average temperature of the molten pool MP satisfies the third reference range, that is, if the determination unit 57 determines that the energy density ED can be maintained within a desired range by changing the molding conditions (i.e., the occurrence of molding defects can be suppressed), the process proceeds to step S65. If the average temperature of the molten pool MP does not satisfy the third reference range, that is, if the determination unit 57 determines that the energy density ED cannot be maintained within a desired range by changing the molding conditions (i.e., the occurrence of molding defects cannot be suppressed), the process proceeds to step S68, which will be described later. Furthermore, the third reference range described above may be set so that, when the molding conditions are changed, the energy density ED is not the only value that can be maintained, and the power density PD and temperature distribution T(r) are kept within the desired range. Also, the average temperature range, which is the third reference range, may be the temperature range from between the melting point and the liquidus temperature of the powder material P used to between the melting point and the solidus temperature. The third reference range is stored in the memory unit 58 in advance.

[0234] In step S65, the determination unit 57 determines whether the average temperature of the molten pool MP is higher than or lower than the second reference range. If the average temperature of the molten pool MP is higher than the second reference range, i.e., the energy density ED of the energy absorbed by the powder material P is excessive, but the determination unit 57 determines that it is possible to bring the value of the energy density ED to the desired range by changing the molding conditions, the process proceeds to step S66. If the average temperature of the molten pool MP is lower than the second reference range, i.e., the energy density ED of the energy absorbed by the powder material P is insufficient, but the determination unit 57 determines that it is possible to bring the value of the energy density ED to the desired range by changing the molding conditions, the process proceeds to step S67.

[0235] In step S66, the calculation unit 56 generates modification information to change the molding conditions so that the value of energy density ED is reduced in order to bring the value of energy density ED within the desired range. The reason for reducing the value of energy density ED is as follows: If the average temperature of the molten pool MP is greater than the second reference range, it means that the amount of heat to the molten pool MP is greater than the amount of heat that is expected to be obtained with the currently set molding conditions, and the temperature of the molten pool MP is too high. For this reason, it is estimated that the energy density ED of the energy absorbed by the powder material P is excessive.

[0236] To reduce the energy density ED and decrease the amount of heat transferred to the powder material P, one approach is to decrease the output of the laser beam from the irradiation unit 32, thereby reducing the energy received by the powder material P. Alternatively, increasing the flow rate and velocity of the inert gas, and cooling the surface of the material layer to lower the temperature of the powder material P, can be considered to increase the amount of heat required for the temperature of the powder material P to rise to a desired temperature (e.g., melting point) due to laser irradiation.

[0237] Furthermore, because the temperature of the powder material P before irradiation with laser light is higher than expected, it is possible that the amount of heat required for the powder material P to reach the desired temperature is reduced. In this case, it is possible to reduce the influence of heat from the formed solidified layer on the powder material P by lowering the temperature of the base plate 311 to lower the temperature of the powder material P before irradiation with laser light, or by extending the time until the material layer is formed on the solidified layer and cooling the solidified layer with an inert gas, or by at least one of these measures. Moreover, because the thickness of the material layer formed on the solidified layer is thin in the Z direction, it is also possible that the heat from the solidified layer is easily conducted to the upper part of the material layer (Z direction + side). In such cases, it is possible to increase the thickness of the material layer (i.e., increase the layer thickness) to increase the heat capacity, thereby making it more difficult for the heat from the already formed solidified layer to be conducted to the upper part of the material layer.

[0238] Furthermore, because the scanning distance when scanning the laser beam is long, the material layer may be heated for a longer period due to the irradiation of the laser beam, potentially causing a rise in temperature. For this reason, it is conceivable to set the scanning path so that the scanning distance when scanning the laser beam is shortened, thereby reducing the time the material layer is exposed to the irradiation of the laser beam and affected by heat. It is also conceivable to increase the scanning speed of the laser beam by the scanning unit 33, thereby shortening the time the laser beam irradiates the same position on the material layer and reducing the amount of energy absorbed by the powder material P per unit time. Additionally, because the spot size of the laser beam is small, the amount of heat may be concentrated in a narrow area of ​​the material layer, potentially resulting in a large amount of energy in the material layer per unit area. Therefore, it is conceivable to increase the spot size to suppress the concentration of heat generated by the laser beam in a narrow area of ​​the material layer.

[0239] Furthermore, because the scanning pitch is small, there is a possibility that the influence of heat conducted from the already solidified solidified region BE to the molten pool MP is significant. Therefore, it is also possible to widen the scanning pitch to suppress the influence of heat conducted from the already solidified solidified region BE. Additionally, if the density of the material layer is high, the heat generated by the irradiation of the laser light may be more easily conducted within the material layer. Therefore, it is also possible to reduce the pressure applied to the powder material P by the blade 221 to lower the density, thereby making it more difficult for heat to conduct through the material layer.

[0240] Based on the above reasoning, in order to lower the energy density ED during the fabrication of the next solidified layer compared to the current state, the calculation unit 56 sets parameter P L The calculation unit 56 generates change information so that at least one of the following changes to the molding conditions is made: Parameter P L A change in the build conditions related to parameter P0 is to lower the laser power. A change in the build conditions related to parameter P0 is at least one of increasing the flow rate and velocity of the inert gas, lowering the power of the heater 313 to lower the temperature of the base plate 311, extending the waiting time of the blade 221, or changing the scanning path. A change in the build conditions related to parameter ρ is to lower the pressure that the blade 221 applies to the material layer. A change in the build conditions related to parameter v is to increase the scanning speed. A change in the build conditions related to parameter Δy is at least one of increasing the spot size of the laser beam or increasing the scanning pitch. A change in the build conditions related to parameter Δz is to increase the layer thickness.

[0241] The calculation unit 56 generates change information by referring to data stored in the storage unit 58 in advance, which associates parameter values ​​with molding condition values, as described in Figures 10, 11, and 12 above. The output unit 55 outputs the change information generated by the calculation unit 56 as status information to the setting unit 59 (at least one of the material control unit 51, molding control unit 52, and housing control unit 53). When the material control unit 51 receives change information, the material control unit 51 causes the recoater 22 to perform at least one of the following operations. In this case, the operation of the recoater 22 includes moving the blade 221 after a new waiting time based on the change information has elapsed, and moving the blade 221 with a new pressure based on the change information. When the molding control unit 52 receives change information, the molding control unit 52 causes at least one of the irradiation unit 32, scanning unit 33, and heater 313 to perform at least one of the following operations. In this case, the operation of the irradiation unit 32 includes emitting laser light with a new laser output based on the change information and moving the focus lens 323 to a new position in the X direction based on the change information. The operation of the scanning unit 33 is to drive the galvanometer mirrors 331 and 332 with a new tilt angle or tilt angle change speed based on the change information. The operation of the heater 313 is to operate with a new heating output based on the change information. If the housing control unit 53 receives change information, the housing control unit 53 operates the intake device 131 and exhaust device 14 with new valve openings and exhaust volumes based on the change information. After that, the process returns to step S61.

[0242] In step S67, the calculation unit 56 generates modification information to change the molding conditions so that the value of the energy density ED is increased in order to bring the value of the energy density ED into the desired range. The reason for increasing the energy density ED is as follows: If the average temperature of the molten pool MP is lower than the second reference range, it means that the amount of heat to the molten pool MP is less than the amount of heat that is expected to be obtained with the currently set molding conditions, and the temperature of the molten pool MP is too low. Therefore, it is estimated that the energy density ED of the energy absorbed by the powder material P is insufficient.

[0243] In this case, the calculation unit 56 generates modification information to increase the value of the energy density ED, using the opposite approach to the approach in step S66 described above. The calculation unit 56 generates modification information to increase the parameter P L The calculation unit 56 generates change information so that at least one of the following changes to the molding conditions is made: parameter P L A change in the build condition related to parameter P0 is to increase the laser power. A change in the build condition related to parameter P0 is at least one of the following: decreasing the inert gas flow rate and velocity, increasing the output of heater 313 to raise the temperature of base plate 311, shortening the waiting time of blade 221, and changing the scanning path. A change in the build condition related to parameter ρ is to increase the pressure that blade 221 applies to the material layer. A change in the build condition related to parameter v is to decrease the scanning speed. A change in the build condition related to parameter Δy is at least one of the following: decreasing the laser beam spot size and decreasing the scanning pitch. A change in the build condition related to parameter Δz is to decrease the layer thickness.

[0244] The calculation unit 56 generates change information by referring to data stored in the storage unit 58 in advance, which associates parameter values ​​with molding condition values, as described in Figures 10, 11, and 12 above. The output unit 55 outputs the change information generated by the calculation unit 56 as status information to the setting unit 59 (at least one of the material control unit 51, molding control unit 52, and housing control unit 53). When the material control unit 51 receives change information, the material control unit 51 causes the recoater 22 to perform at least one of the following operations. In this case, the operation of the recoater 22 includes moving the blade 221 after a new waiting time based on the change information has elapsed, and moving the blade 221 with a new pressure based on the change information. When the molding control unit 52 receives change information, the molding control unit 52 causes at least one of the irradiation unit 32, scanning unit 33, and heater 313 to perform at least one of the following operations. In this case, the operation of the irradiation unit 32 includes emitting laser light with a new laser output based on the change information and moving the focus lens 323 to a new position in the X direction based on the change information. The operation of the scanning unit 33 is to drive the galvanometer mirrors 331 and 332 with a new tilt angle or tilt angle change speed based on the change information. The operation of the heater 313 is to operate with a new heating output based on the change information. If the housing control unit 53 receives change information, the housing control unit 53 operates the intake device 131 and exhaust device 14 with new valve openings and exhaust volumes based on the change information. After that, the process returns to step S61. In steps S66 and S67, the calculation unit 56 may generate change information by providing the difference between the new molding condition value and the current molding condition value.

[0245] In step S68 shown in Figure 14, the determination unit 57 determines whether the average temperature of the molten pool MP meets the fourth reference range. The fourth reference range is the range of average temperatures of the molten pool MP in which the energy density ED can be kept within a desired range by performing predetermined repairs on the formed solidified layer. In other words, the determination unit 57 determines in step S68 whether or not repairs to the solidified layer are necessary. The maximum value of the fourth reference range is a value that is larger by a predetermined percentage than the maximum value of the third reference range. The minimum value of the fourth reference range is a value that is smaller by a predetermined percentage than the minimum value of the third reference range. Note that the fourth reference range may also be the range between the vicinity of the maximum value and the vicinity of the minimum value. If the average temperature of the molten pool MP meets the fourth reference range, that is, if the determination unit 57 determines that the energy density ED can be brought within a desired range by repairing the formed solidified layer, the process proceeds to step S69. In this case, if the average temperature of the melting pool MP meets the third reference range, the determination unit 57 determines that it is necessary to generate change information, and if it does not meet the third reference range, the determination unit 57 determines that it is necessary to repair the solidified layer.

[0246] If the average temperature of the molten pool MP does not meet the fourth reference range, that is, if the determination unit 57 determines that the energy density ED cannot be brought to the desired range even if the formed solidified layer is repaired, the process proceeds to step S70. Furthermore, the fourth reference range described above may be set so that, when the solidified layer is repaired, the energy density ED, as well as the power density PD and temperature distribution T(r), are maintained within a desired range. Also, the average temperature range, which is the fourth reference range, may be a temperature range from the temperature between the melting point and the liquidus temperature of the powder material P used to the temperature between the melting point and the solidus temperature. The fourth reference range is stored in the memory unit 58 in advance.

[0247] In step S69, the calculation unit 56 generates repair information for performing repair processing. As repair processing, the molding apparatus 1 performs a remelt process, for example, by irradiating the molded solidified layer with laser light again to melt and solidify it. In this case, the calculation unit 56 generates repair information based on the difference between the average temperature of the molten pool MP obtained from the temperature data image and an arbitrary value (e.g., the median) within a second reference range, which includes the molding conditions for the irradiation unit 32 to irradiate with laser light, namely the laser output, beam quality, oscillation mode, laser wavelength, laser polarization state, laser intensity distribution, and laser spot size. The difference between the average temperature of the molten pool MP and an arbitrary value (e.g., the median) within the second reference range, and the values ​​of the molding conditions for the irradiation unit 32 to irradiate with laser light are stored in the storage unit 58 as associated data. The calculation unit 56 generates repair information by referring to this data. The output unit 55 outputs the repair information generated by the calculation unit 56 to the molding control unit 52. The molding control unit 52 causes the irradiation unit 32 to output laser light based on the repair information to perform the repair process. After that, the process returns to step S61 in Figure 13.

[0248] In step S70, the calculation unit 50 stops the subsequent printing of the three-dimensional object and terminates the process. In this case, it can also be said that the determination unit 57 determined in step S68 that repair of the solidified layer is necessary if the average temperature of the molten pool MP meets the fourth reference range, and determined that printing must be stopped if the average temperature of the molten pool MP does not meet the fourth reference range. The process in step S71, which proceeds when the average temperature of the molten pool MP meets the second reference range, is the same as the process in step S38 in Figure 10. By performing the above process, the basic conditions for the melting and solidification of the powder material P are ensured even when forming the next solidified layer, suppressing the occurrence of molding defects in the solidified layer due to insufficient or excessive melting, and repairing any molding defects that occur in the formed solidified layer.

[0249] Furthermore, in steps S66 and S67 of the flowchart shown in Figure 13 above, the calculation unit 56 performs the calculation of parameter PL Which of the parameters P0, ρ, v, Δy, and Δz is changed or left unchanged depends on the user's requirements for the fabrication of the three-dimensional object. For example, if the user wants to avoid an increase in fabrication time, the calculation unit 56 may choose not to change the value of parameter v in step S67 above, so as not to reduce the scanning speed of the laser beam. Furthermore, in steps S66 and S67, the calculation unit 56 may generate change information for the printing conditions that affect the energy density ED in addition to the printing conditions described above, and that can be changed when printing the next layer. For example, the calculation unit 56 may generate change information for the oscillation mode of the laser light of the irradiation unit 32, the intensity distribution of the laser light, the movement speed of the blade 221, and the moisture absorption of the powder material P. Furthermore, as described above, the calculation unit 56 may inform the user of the specified target information and accept the user's specifications in order to determine the parameters and molding conditions for generating change information.

[0250] Next, the following case is given as an example of the processing when a change is made during the fabrication of the next layer. The detection unit 54 obtains information about the temperature of the molten pool MP and its vicinity as the molten state during the fabrication of the solidified layer. The calculation unit 56 generates change information based on the temperature information obtained by the detection unit 54 during the fabrication of the solidified layer, so as to keep the value of the temperature distribution T(r) when a new solidified layer is fabricated on top of the solidified layer within a desired range. Note that the calculation unit 56 is not limited to generating change information to keep the value of the temperature distribution T(r) within a desired range, but may also generate change information to keep at least one of the power density PD value, energy density ED value, and temperature distribution T(r) value within a desired range.

[0251] Each process in the flowcharts shown in Figures 15 and 16 is stored in the memory unit 58 of the arithmetic unit 50, read by the arithmetic unit 50, and executed. The processes in steps S81 and S82 are the same as those in steps S61 and S62 of the flowchart shown in Figure 13. However, the detection unit 54 uses the temperature history described above to determine the temperature gradient, which is the change in temperature over time at a predetermined location in the material layer, as information about the temperature of the molten pool MP and its vicinity. In this case, the detection unit 54 determines the temperature before melting and the temperature during melting at the same location in the material layer by determining the temperature history as described above. Then, the detection unit 54 calculates the change in temperature over time when the temperature changes from the temperature before melting to the temperature during melting, based on the time information of the image data used to detect the temperature history. The detection unit 54 determines this change in time as the temperature gradient. Furthermore, the detection unit 54 generates temperature image data and stores it in the storage unit 58 when the solidified layer is being fabricated, and after the fabrication of one solidified layer is completed, the temperature gradient of the molten pool MP may be determined from each of the multiple temperature image data stored in the storage unit 58.

[0252] In step S83, the determination unit 57 determines whether the temperature gradient of the molten pool MP, as determined by the detection unit 54, satisfies a predetermined second reference range. The second reference range is the range of the temperature gradient of the molten pool MP required to maintain the temperature distribution T(r) within a desired range, and is set, for example, based on the results of various tests and simulations performed by the user, similar to step S63 described above. If the determination unit 57 determines that the temperature gradient does not satisfy the second reference range, the process proceeds to step S84. If the determination unit 57 determines that the temperature gradient satisfies the second reference range, the process proceeds to step S91, which will be described later. In other words, in step S83, the determination unit 57 determines whether or not it is necessary to generate change information. Furthermore, the second reference range described above is not limited to the temperature distribution T(r), but may be set so that the power density PD and energy density ED are kept within a desired range. Also, the range of the temperature gradient, which is the second reference range, may be the range from the temperature gradient between the melting point and the liquidus temperature of the powder material P used to the temperature gradient between the melting point and the solidus temperature.

[0253] In step S84, the determination unit 57 determines whether the temperature gradient obtained by the detection unit ...

Claims

1. A fabrication system for creating a three-dimensional object consisting of a layered unmelted material layer made of unmelted powder material, and a solidified layer formed by irradiation with energy rays in which at least a portion of the unmelted material layer has solidified, A light-receiving unit that receives light from the unmelted material layer, The system comprises a molding unit that fabricates the three-dimensional object under fabrication conditions set based on information regarding at least one of the flatness, density, layer thickness, and shape of the unmelted material layer, which is determined based on the light reception results at the light receiving unit, The aforementioned molding conditions include a molding system that includes the intensity distribution of the energy rays.

2. A molding system according to claim 1, wherein the molding conditions further include at least one of material layer formation conditions for forming the unmelted material layer and conditions for the powder material.

3. A fabrication system according to claim 1, wherein the intensity distribution of the energy rays includes a Gaussian distribution or a top-hat distribution.

4. In the molding system according to claim 1, the molding conditions further include scanning conditions for scanning the energy rays, The scanning conditions include the scanning pitch of the energy line in the fabrication system.

5. In the molding system according to claim 1, the molding conditions further include scanning conditions for scanning the energy rays, The scanning conditions include a fabrication system that includes the scanning path of the energy line.

6. In the molding system described in claim 2, The material layer formation conditions include at least one of the following: the movement speed of the material layer forming member that forms the unmelted material layer; the pressure applied to the powder material by the material layer forming member; and the waiting time until the formation of the material layer on top of the solidified layer begins.

7. In the molding system according to claim 1, The molding conditions further include a molding system that includes the oscillation mode of the energy rays.

8. In the molding system according to claim 7, The aforementioned oscillation mode includes continuous oscillation or pulsed oscillation in the fabrication system.

9. In the molding system according to claim 1, The molding conditions further include support conditions related to the support portion that supports the unmelted material layer and the solidified layer, The support condition includes the temperature of the support in the molding system.

10. In the molding system according to claim 1, The molding conditions further include design data related to the shape of the solidified layer or the three-dimensional molded object. The aforementioned design data includes shape data of the support portion that supports the solidified layer or the three-dimensional molded object, and is part of a molding system.

11. In the molding system according to claim 1, The molding system further includes conditions relating to the atmosphere inside the housing that causes at least a portion of the unmelted material layer to melt by irradiation with the energy rays.

12. In the molding system according to any one of claims 1 to 11, The molding system further includes at least one of the following conditions: the oscillation mode of the energy ray, the wavelength of the energy ray, the polarization state of the energy ray, the output power of the energy ray, and the spot size of the energy ray that irradiates the material layer.

13. In the molding system according to any one of claims 1 to 11, The light-receiving unit is a fabrication system that receives light from the unmelted material layer when the energy rays are not irradiating the unmelted material layer.

14. In the molding system according to any one of claims 1 to 11, The molding unit is a molding system that molds the three-dimensional object under molding conditions set based on the state of fluidity of the powder material that forms the unmelted material layer, which is determined based on the light reception result.

15. In the molding system according to any one of claims 1 to 11, The system further comprises a calculation unit that generates the molding conditions based on the state of the shape of the unmelted material layer determined based on the light reception results, The molding unit is a molding system that molds the three-dimensional object using the generated molding conditions.

16. In the molding system described in claim 2, The material layer formation conditions further include a molding system comprising at least one of the shape of the material layer forming member that forms the unmelted material layer, the material of the material layer forming member, and the layer thickness of the material layer.

17. In the molding system according to any one of claims 1 to 11, The molding unit is a molding system that performs molding on the unmelted material layer, which is made of the powder material supplied to the top of a solidified layer, or on the unmelted material layer, which is made of the powder material supplied to the top of the solidified layer, by melting at least a portion of the unmelted material layer, whose shape has been determined by energy rays, under the set molding conditions.

18. In the molding system according to any one of claims 1 to 11, The molding unit is a molding system that, after the molding of the aforementioned three-dimensional object is completed, performs molding on a newly molded three-dimensional object according to the set molding conditions.

19. In the molding system according to claim 5, The scanning conditions further include the scanning speed of the energy line in the fabrication system.

20. In the molding system according to claim 11, A molding system in which the conditions related to the atmosphere inside the enclosure include at least one of the following conditions: the type of inert gas introduced into the enclosure, the flow rate of the inert gas introduced into the enclosure, the flow velocity of the inert gas introduced into the enclosure, the oxygen concentration inside the enclosure, the pressure inside the enclosure, and the temperature inside the enclosure.

21. In the molding system according to claim 9, The aforementioned support condition further includes a molding system that includes the type of the support.

22. In the molding system according to claim 10, The aforementioned design data further includes a fabrication system comprising at least one data set of the shape data of the solidified layer to be fabricated, fabrication orientation data, and the shape data of the three-dimensional fabricated object.

23. In the molding system according to any one of claims 1 to 11, The conditions relating to the powder material include at least one of the following conditions: the particle size distribution of the powder material, the moisture absorption of the powder material, the oxygen concentration of the powder material, and the material of the powder material.

24. In the molding system according to any one of claims 1 to 11, A molding system further comprising a determination unit that determines whether or not the formed material layer needs to be repaired based on the state of the shape of the unmelted material layer determined based on the light reception results.

25. In the molding system according to claim 14, A molding system further comprising a determination unit that determines whether or not a heat treatment of the powder material is necessary based on the state of the fluidity of the powder material determined based on the light reception results.

26. In the molding system according to any one of claims 1 to 11, A molding system further comprising a determination unit that determines whether it is necessary to generate change information for changing the set molding conditions based on the state of the shape of the unmelted material layer determined based on the light reception results.

27. In the molding system according to claim 24, The molding system comprises a determination unit which determines that if the shape of the unmelted material layer determined based on the light reception result satisfies a first standard value, it is necessary to generate change information to change the set molding conditions, and if the shape of the unmelted material layer determined based on the light reception result does not satisfy the first standard value, it determines that repair of the unmelted material layer is necessary.

28. In the molding system according to claim 24, The manufacturing system includes a determination unit which determines that if the shape of the unmelted material layer determined based on the light reception result satisfies a second standard value, repair of the unmelted material layer is necessary, and if the shape of the unmelted material layer determined based on the light reception result does not satisfy the second standard value, it determines that the manufacturing of the three-dimensional object needs to be stopped.

29. In the molding system according to claim 24, A molding system that, when the determination unit determines that the unmelted material layer needs repair, removes the formed unmelted material layer and forms a new unmelted material layer.

30. In the molding system according to claim 25, A molding system that, based on the state of fluidity of the powder material determined from the light reception results, determines that a heat treatment of the powder material is necessary, and then performs a heat treatment on the powder material.

31. In the molding system according to any one of claims 1 to 11, The light receiving unit includes an image acquisition unit that receives light from the unmelted material layer and acquires image data of the unmelted material layer as a result of the light receiving. The molding unit is a molding system that molds the three-dimensional object using molding conditions set based on the state of the shape of the unmelted material layer, which is determined based on the image data acquired by the image acquisition unit.

32. In the molding system according to claim 31, The system further comprises a light projection unit that projects light with a predetermined intensity distribution onto the unmelted material layer. The image acquisition unit acquires image data of at least a portion of the region on which the light is projected in the unmelted material layer as the light reception result. The molding unit of the molding system is a molding system that molds the three-dimensional object under molding conditions set based on the state of the shape of the unmelted material layer, which is determined based on the image data acquired by the image acquisition unit.

33. In the molding system according to claim 32, A molding system further comprising an irradiation unit for irradiating the aforementioned energy rays.

34. In the molding system described in claim 33, The aforementioned irradiation unit also serves as the aforementioned light projection unit in this molding system.

35. In the molding system according to any one of claims 1 to 11, The system further includes a detection unit that determines the state of the shape of the unmelted material layer based on the light reception result at the light receiving unit, The molding unit is a molding system that molds the three-dimensional object according to the molding conditions set based on the shape of the unmelted material layer determined by the detection unit.

36. A fabrication method for creating a three-dimensional object comprising a layered unmelted material layer made of unmelted powder material, and a solidified layer formed by irradiation with energy rays in which at least a portion of the unmelted material layer has solidified, Receiving light from the aforementioned unmelted material layer, This includes fabricating the three-dimensional object under fabrication conditions set based on information regarding at least one of the flatness, density, layer thickness, and shape of the unmelted material layer, which is determined based on the light reception results at the light receiving unit, The aforementioned fabrication conditions include a fabrication method that includes the intensity distribution of the energy rays.

37. A molding method according to claim 36, wherein the molding conditions further include at least one of material layer formation conditions for forming the unmelted material layer and conditions for the powder material.

38. A fabrication method according to claim 36, wherein the intensity distribution of the energy rays includes a Gaussian distribution or a top-hat distribution.

39. In the fabrication method according to claim 36, the fabrication conditions further include scanning conditions for scanning the energy rays, The scanning conditions include a fabrication method that includes the scanning pitch of the energy line.

40. In the fabrication method according to claim 36, the fabrication conditions further include scanning conditions for scanning the energy rays, The scanning conditions are a fabrication method that includes the scanning path of the energy line.

41. In the molding method described in claim 37, The material layer formation condition is a molding method comprising at least one of the moving speed of the material layer forming member that forms the unmelted material layer, the pressure applied to the powder material by the material layer forming member, and the waiting time until the formation of the material layer on top of the solidified layer begins.

42. In the molding method described in claim 36, The above-mentioned molding conditions further include a molding method that includes the oscillation mode of the energy rays.

43. The molding method according to claim 41, wherein the oscillation mode includes continuous oscillation or pulse oscillation.

44. In the molding method described in claim 36, The molding conditions further include support conditions related to the support portion that supports the unmelted material layer and the solidified layer, The support condition includes a molding method that includes the temperature of the support.

45. In the molding method described in claim 36, The molding conditions further include design data related to the shape of the solidified layer or the three-dimensional molded object. The aforementioned design data includes shape data of the solidified layer or the support portion that supports the three-dimensional object, and is a method for fabrication.

46. In the molding method according to any one of claims 36 to 45, The molding conditions further include conditions relating to the atmosphere inside the housing that melts at least a portion of the unmelted material layer by irradiation with the energy rays.

47. A computer-readable medium recording a molding program that causes a computer to execute the processing in the molding method described in any one of claims 36 to 46.

48. An information acquisition device used for setting the fabrication conditions of a three-dimensional object, comprising a layered unmelted material layer made of unmelted powder material, and a solidified layer formed by irradiation with energy rays in which at least a portion of the unmelted material layer has solidified, A light-receiving unit that receives light from the unmelted material layer, Equipped with, The three-dimensional object is fabricated under fabrication conditions set based on information regarding at least one of the flatness, density, layer thickness, and shape of the unmelted material layer, which is determined based on the light reception result from the unmelted material layer at the light receiving unit. The molding conditions are provided by an information acquisition device that includes the intensity distribution of the energy rays.

49. The molding system according to claim 48, wherein the molding conditions further include at least one of material layer formation conditions for forming the unmelted material layer and conditions for the powder material.

50. An information acquisition device according to claim 48, wherein the intensity distribution of the energy rays includes a Gaussian distribution or a top-hat distribution.

51. In the information acquisition device according to claim 48, the molding conditions further include scanning conditions for scanning the energy rays, The scanning conditions include the scanning pitch of the energy line, as well as the information acquisition device.

52. In the information acquisition device according to claim 48, the molding conditions further include scanning conditions for scanning the energy rays, The scanning conditions include an information acquisition device that includes the scanning path of the energy line.

53. In the information acquisition device described in claim 49, The information acquisition device includes at least one of the material layer formation conditions: the movement speed of the material layer forming member that forms the unmelted material layer; the pressure applied to the powder material by the material layer forming member; and the waiting time until the formation of the material layer on top of the solidified layer begins.

54. In the information acquisition device described in claim 48, The aforementioned molding conditions further include an information acquisition device that includes the oscillation mode of the energy rays.

55. An information acquisition device according to claim 54, wherein the oscillation mode includes continuous oscillation or pulse oscillation.

56. In the information acquisition device described in claim 48, The molding conditions further include support conditions related to the support portion that supports the unmelted material layer and the solidified layer, The support condition is an information acquisition device that includes the temperature of the support.

57. In the information acquisition device described in claim 48, The molding conditions further include design data related to the shape of the solidified layer or the three-dimensional molded object. The design data includes shape data of the solidified layer or the support portion that supports the three-dimensional molded object.

58. In the information acquisition device described in claim 48, The information acquisition device further includes conditions related to the atmosphere inside the housing in which the molding conditions are melted by irradiation with the energy rays, which melt at least a portion of the unmelted material layer.

59. In the information acquisition device according to any one of claims 48 to 58, The molding conditions further include at least one condition of the energy ray oscillation mode, the energy ray wavelength, the polarization state of the energy ray, the output power of the energy ray, and the spot size of the energy ray irradiating the material layer.

60. In the information acquisition device according to any one of claims 48 to 58, The light-receiving unit is an information acquisition device that receives light from the unmelted material layer when the energy rays are not irradiating the unmelted material layer.

61. In the information acquisition device according to any one of claims 48 to 58, An information acquisition device that fabricates a three-dimensional object under fabrication conditions set based on the fluidity state of the powder material forming the unmelted material layer, which is determined based on the light reception results.

62. In the information acquisition device according to any one of claims 48 to 58, The system further comprises a calculation unit that generates the molding conditions based on the state of the shape of the unmelted material layer determined based on the light reception results, An information acquisition device that generates the three-dimensional object using the aforementioned molding conditions.

63. In the information acquisition device described in claim 49, The information acquisition device further includes, for the material layer formation conditions, the shape of the material layer forming member that forms the unmelted material layer, the material of the material layer forming member, and the thickness of the laminated material layer.

64. In the information acquisition device according to any one of claims 48 to 58, An information acquisition device that performs molding on the unmelted material layer, which is made of the powder material supplied to the top of a solidified layer, or on the unmelted material layer, which is made of the powder material supplied to the top of the solidified layer, after melting and solidifying at least a portion of the unmelted material layer, which has been determined to have a shape relating to the shape of the unmelted material layer, by energy rays, under the set molding conditions.

65. In the information acquisition device according to any one of claims 48 to 58, The molding unit is an information acquisition device that, after the molding of the three-dimensional object is completed, performs molding on a new three-dimensional object according to the set molding conditions.

66. In the information acquisition device described in claim 52, The scanning conditions further include the scanning speed of the energy line, as well as the information acquisition device.

67. In the information acquisition device described in claim 58, An information acquisition device in which conditions related to the atmosphere inside the enclosure include at least one of the following conditions: the type of inert gas introduced into the enclosure, the flow rate of the inert gas introduced into the enclosure, the flow velocity of the inert gas introduced into the enclosure, the oxygen concentration inside the enclosure, the pressure inside the enclosure, and the temperature inside the enclosure.

68. In the information acquisition device described in claim 56, The support condition further includes an information acquisition device that includes the type of the support.

69. In the information acquisition device described in claim 57, The design data further includes an information acquisition device that includes at least one of the following data: shape data of the solidified layer to be fabricated, fabrication orientation data, and shape data of the three-dimensional fabricated object.

70. In the information acquisition device described in claim 49, The information acquisition device includes at least one of the following conditions related to the powder material: the particle size distribution of the powder material, the moisture absorption of the powder material, the oxygen concentration of the powder material, and the material of the powder material.

71. In the information acquisition device according to any one of claims 48 to 58, An information acquisition device further comprising a determination unit that determines whether or not the formed material layer needs to be repaired based on the state of the shape of the unmelted material layer determined based on the light reception results.

72. In the information acquisition device described in claim 61, An information acquisition device further comprising a determination unit that determines whether or not a heat treatment of the powder material is necessary based on the state of the fluidity of the powder material determined based on the light reception results.

73. In the information acquisition device according to any one of claims 48 to 58, An information acquisition device further comprising a determination unit that determines whether it is necessary to generate change information for changing the set molding conditions based on the state of the shape of the unmelted material layer determined based on the light reception results.

74. In the information acquisition device according to claim 71, The determination unit determines that if the shape of the unmelted material layer determined based on the light reception result satisfies a first standard value, it is necessary to generate change information to change the set molding conditions, and if the shape of the unmelted material layer determined based on the light reception result does not satisfy the first standard value, it determines that repair of the unmelted material layer is necessary.

75. In the information acquisition device according to claim 71, The determination unit determines that if the shape of the unmelted material layer determined based on the light reception result satisfies a second standard value, repair of the unmelted material layer is necessary, and if the shape of the unmelted material layer determined based on the light reception result does not satisfy the second standard value, it determines that the molding of the three-dimensional object needs to be stopped.

76. In the information acquisition device according to claim 71, If the determination unit determines that the unmelted material layer needs repair, the information acquisition device removes the formed unmelted material layer and forms a new unmelted material layer.

77. In the information acquisition device according to claim 72, An information acquisition device in which, based on the state of fluidity of the powder material determined based on the light reception result, the determination unit determines that heat treatment of the powder material is necessary, and then heat treatment is performed on the powder material.

78. In the information acquisition device according to any one of claims 48 to 58, The light receiving unit includes an image acquisition unit that receives light from the unmelted material layer and acquires image data of the unmelted material layer as a result of the light receiving. An information acquisition device that fabricates a three-dimensional object under fabrication conditions set based on the state of the shape of the unmelted material layer, which is determined based on the image data acquired by the image acquisition unit.

79. In the information acquisition device according to claim 78, The system further comprises a light projection unit that projects light with a predetermined intensity distribution onto the unmelted material layer. The image acquisition unit acquires image data of at least a portion of the region on which the light is projected in the unmelted material layer as the light reception result. An information acquisition device that fabricates a three-dimensional object under fabrication conditions set based on the state of the shape of the unmelted material layer, which is determined based on the image data acquired by the image acquisition unit.

80. In the information acquisition device according to any one of claims 48 to 58, The system further includes a detection unit that determines the state of the shape of the unmelted material layer based on the light reception result at the light receiving unit, An information acquisition device that determines the three-dimensional object to be fabricated under the fabrication conditions set based on the shape of the unmelted material layer determined by the detection unit.

81. In the information acquisition device according to any one of claims 48 to 58, Furthermore, the information acquisition device includes an output unit that outputs the light reception result from the light receiving unit.

82. An information processing method used for setting the fabrication conditions of a three-dimensional object comprising a layered unmelted material layer made of unmelted powder material, and a solidified layer formed by irradiation with energy rays in which at least a portion of the unmelted material layer has solidified, Receiving light from the aforementioned unmelted material layer, Includes, The three-dimensional object is fabricated under fabrication conditions set based on information regarding at least one of the flatness, density, layer thickness, and shape of the unmelted material layer, which is determined based on the light reception results from the unmelted material layer. The molding conditions include an information processing method that includes the intensity distribution of the energy rays.

83. The information processing method according to claim 82, wherein the molding conditions further include at least one of the material layer formation conditions for forming the unmelted material layer and the conditions for the powder material.

84. The information processing method according to claim 82, wherein the intensity distribution of the energy lines includes a Gaussian distribution or a top-hat distribution.

85. In the information processing method according to claim 82, the molding conditions further include scanning conditions for scanning the energy rays, The scanning conditions include an information processing method that includes the scanning pitch of the energy line.

86. In the information processing method according to claim 82, the molding conditions further include scanning conditions for scanning the energy rays, The scanning conditions include an information processing method that includes the scanning path of the energy line.

87. In the information processing method described in claim 83, The material layer formation condition is an information processing method that includes at least one of the following: the movement speed of the material layer forming member that forms the unmelted material layer; the pressure applied to the powder material by the material layer forming member; and the waiting time until the formation of the material layer on top of the solidified layer begins.

88. In the information processing method described in claim 82, The above-mentioned molding conditions further include an information processing method that includes the oscillation mode of the energy ray.

89. The information processing method according to claim 88, wherein the oscillation mode includes continuous oscillation or pulse oscillation.

90. In the information processing method described in claim 82, The molding conditions further include support conditions related to the support portion that supports the unmelted material layer and the solidified layer, The support condition is an information processing method that includes the temperature of the support.

91. In the information processing method described in claim 82, The molding conditions further include design data related to the shape of the solidified layer or the three-dimensional molded object. The design data includes shape data of the solidified layer or the support portion that supports the three-dimensional object, and is an information processing method.

92. In the information processing method described in claim 82, The molding conditions further include conditions related to the atmosphere inside the housing that causes at least a portion of the unmelted material layer to melt by irradiation with the energy rays.

93. In the information processing method described in claims 82 to 92, Furthermore, an information processing method that includes outputting the light reception result.

94. A computer read medium recording an information processing program that causes a computer to perform the processing described in any one of claims 82 to 93.

95. A computing device used in a fabrication apparatus that fabricates a three-dimensional object consisting of a layered unmelted material layer made of unmelted powder material, and a solidified layer formed by irradiation with energy rays in which at least a portion of the unmelted material layer has solidified, The system includes a detection unit configured to detect information relating to at least one of the flatness, density, thickness, and shape of the unmelted material layer, The molding conditions of the molding apparatus are set based on the information detected by the detection unit. The aforementioned molding conditions are calculated using a computing device that includes the intensity distribution of the energy rays.

96. The calculation device according to claim 95, wherein the molding conditions further include at least one of material layer formation conditions for forming the unmelted material layer and conditions for the powder material.

97. The computing device according to claim 95, wherein the intensity distribution of the energy lines includes a Gaussian distribution or a top-hat distribution.

98. In the computing device according to claim 95, the molding conditions further include scanning conditions for scanning the energy rays, The scanning conditions include a computing device that includes the scanning pitch of the energy line.

99. In the arithmetic device according to claim 98, The aforementioned scanning conditions further include a computing device that includes the scanning path of the energy line.

100. In the arithmetic device according to claim 96, The calculation device includes at least one of the material layer formation conditions: the movement speed of the material layer forming member that forms the unmelted material layer; the pressure applied to the powder material by the material layer forming member; and the waiting time until the formation of the material layer on top of the solidified layer begins.

101. In the arithmetic device according to claim 95, The aforementioned fabrication conditions further include a computing device that includes the oscillation mode of the energy rays.

102. In the computing device according to claim 101, The aforementioned oscillation mode includes continuous oscillation or pulse oscillation in the computing device.

103. In the arithmetic device according to claim 95, The molding conditions further include support conditions related to the support portion that supports the unmelted material layer and the solidified layer, The support condition includes a calculation device that includes the temperature of the support.

104. In the arithmetic device according to claim 95, The molding conditions further include design data related to the shape of the solidified layer or the three-dimensional molded object. The design data includes a computing device that includes shape data for the solidified layer or the support portion that supports the three-dimensional object.

105. In the arithmetic device according to claim 95, The calculation device further includes conditions relating to the atmosphere inside the housing that causes at least a portion of the unmelted material layer to melt by irradiation with the energy rays.

106. In the arithmetic device according to any one of claims 95 to 105, The molding conditions further include a calculation device comprising at least one of the following conditions: the oscillation mode of the energy ray, the wavelength of the energy ray, and the polarization state of the energy ray.

107. In the computing device according to claim 105, A computing device in which the conditions related to the atmosphere inside the enclosure include at least one of the following conditions: the type of inert gas introduced into the enclosure, the flow rate of the inert gas introduced into the enclosure, the flow velocity of the inert gas introduced into the enclosure, the oxygen concentration inside the enclosure, the pressure inside the enclosure, and the temperature inside the enclosure.

108. In the arithmetic device according to claim 96, The calculation device further includes, for the material layer formation conditions, the shape of the material layer forming member that forms the unmelted material layer, the material of the material layer forming member, and the thickness of the material layer.

109. In the arithmetic device according to any one of claims 95 to 105, The detection unit is a calculation device configured to detect the state of the fluidity of the powder material that forms the unmelted material layer.

110. In the arithmetic device according to any one of claims 95 to 105, A calculation unit generates change information for changing the molding conditions used to fabricate the three-dimensional object, based on the state of the shape of the unmelted material layer detected by the detection unit, A computing device further comprising an output unit that outputs the aforementioned change information.

111. In the computing device according to claim 110, The calculation unit is a calculation device that generates change information for changing the molding conditions related to the powder material supplied to the upper part of the solidified layer, which is obtained by melting and solidifying at least a portion of the unmelted material layer whose shape state has been detected by the detection unit using energy rays, or the molding conditions related to the powder material supplied to the upper part of the solidified layer.

112. In the computing device according to claim 110, The calculation unit is a calculation device that generates change information for changing the printing conditions for a new three-dimensional object to be printed after the printing of the three-dimensional object is completed.

113. In the arithmetic device according to any one of claims 95 to 105, The fabrication conditions further include a calculation device comprising at least one condition of the output of the energy ray and the spot size of the energy ray irradiating the material layer.

114. In the arithmetic device according to any one of claims 95 to 105, The scanning conditions further include a computing device that includes the scanning speed of the energy line.

115. In the computing device according to claim 103, The aforementioned support condition further includes the type of support in the calculation device.

116. In the arithmetic device according to claim 104, The design data further includes a computing device which includes at least one of the following data: shape data of the solidified layer to be fabricated, fabrication orientation data, and shape data of the three-dimensional fabricated object.

117. In the arithmetic device according to claim 96, The calculation device includes at least one of the following conditions for the powder material: the particle size distribution of the powder material, the moisture absorption of the powder material, the oxygen concentration of the powder material, and the material of the powder material.

118. In the arithmetic device according to claim 109, A calculation device further comprising a determination unit that determines whether or not a heat treatment of the powder material is necessary based on the state of the fluidity of the powder material determined by the detection unit.

119. In the computing device according to claim 110, A calculation device further comprising a determination unit that determines whether the formed material layer needs to be repaired and / or whether to generate the change information, based on the state of the shape of the unmelted material layer determined by the detection unit.

120. In the computing device according to claim 119, The determination unit determines that if the shape of the unmelted material layer determined by the detection unit satisfies a first standard value, it is necessary to generate change information to change the set molding conditions, and if the shape of the unmelted material layer determined by the detection unit does not satisfy the first standard value, it determines that repair of the unmelted material layer is necessary.

121. In the computing device according to claim 120, The determination unit determines that repair of the unmelted material layer is necessary if the shape of the unmelted material layer determined by the detection unit satisfies a second standard value, and determines that the printing of the three-dimensional object needs to be stopped if the shape of the unmelted material layer determined by the detection unit does not satisfy the second standard value.

122. In the computing device according to claim 119, If the determination unit determines that the unmelted material layer needs repair, the calculation unit generates repair information for removing the formed unmelted material layer and forming a new unmelted material layer.

123. In the computing device according to claim 118, A computing device further comprising a calculation unit that generates heat treatment information for performing heat treatment on the powder material when the determination unit determines that heat treatment is necessary on the powder material based on the state of fluidity of the powder material determined by the detection unit.

124. In the arithmetic device according to any one of claims 95 to 105, The calculation device further comprises an output unit that outputs the state of the shape of the unmelted material layer detected by the detection unit.

125. A computing device according to any one of claims 95 to 124, The system includes an image acquisition unit that acquires image data of the unmelted material layer, The detection unit of the calculation device is a detection system that detects the state of the shape of the unmelted material layer, which is determined based on the image data acquired by the image acquisition unit.

126. In the detection system according to claim 125, The system further comprises a light projection unit that projects light with a predetermined intensity distribution onto the unmelted material layer. The image acquisition unit acquires image data of at least a portion of the area on which the light is projected in the unmelted material layer. The detection unit of the calculation device is a detection system that detects the state of the shape of the unmelted material layer based on the image data acquired by the image acquisition unit.

127. A molding device, A computing device according to any one of claims 95 to 124, A setting device for setting the molding conditions of the molding apparatus based on information regarding at least one of the flatness, density, layer thickness, and shape of the unmelted material layer output from the calculation device, A molding apparatus comprising: a molding unit that forms a layered unmelted material layer made of unmelted powder material based on the molding conditions set by the setting device, and molds a three-dimensional object from a solidified layer formed by solidifying at least a portion of the unmelted material layer by irradiation with energy rays.

128. A molding device, The detection system according to claim 125 or 126, A setting device for setting the molding conditions of the molding apparatus based on information regarding at least one of the flatness, density, layer thickness, and shape of the unmelted material layer output from the calculation device, A molding apparatus comprising: a molding unit that forms a layered unmelted material layer made of unmelted powder material based on the molding conditions set by the setting device, and molds a three-dimensional object from a solidified layer formed by solidifying at least a portion of the unmelted material layer by irradiation with energy rays.

129. A molding device, A setting device for setting the molding conditions of the molding apparatus based on information relating to at least one of the flatness, density, layer thickness, and shape of the unmelted material layer output from a calculation device according to any one of claims 95 to 124, A molding apparatus comprising: a molding unit that forms a layered unmelted material layer made of unmelted powder material based on the molding conditions set by the setting device, and molds a three-dimensional object from a solidified layer formed by solidifying at least a portion of the unmelted material layer by irradiation with energy rays.

130. A calculation method used in a fabrication apparatus that fabricates a three-dimensional object consisting of a layered unmelted material layer made of unmelted powder material, and a solidified layer formed by irradiation with energy rays in which at least a portion of the unmelted material layer has solidified, The system includes detecting information regarding at least one of the flatness, density, thickness, and shape of the unmelted material layer. The molding conditions of the molding apparatus are set based on the information detected by the detection unit. The molding conditions are calculated using a method that includes the intensity distribution of the energy rays.

131. The calculation method according to claim 130, wherein the molding conditions further include at least one of the material layer formation conditions for forming the unmelted material layer and the conditions for the powder material.

132. The calculation method according to claim 128, wherein the intensity distribution of the energy lines includes a Gaussian distribution or a top-hat distribution.

133. In the calculation method according to claim 130, the molding conditions further include scanning conditions for scanning the energy rays, The scanning conditions include a calculation method that includes the scanning pitch of the energy line.

134. In the calculation method described in claim 133, The aforementioned scanning conditions are a calculation method that further includes the scanning path of the energy line.

135. In the calculation method described in claim 131, The material layer formation condition is calculated using a method that includes at least one of the following: the movement speed of the material layer forming member that forms the unmelted material layer; the pressure applied to the powder material by the material layer forming member; and the waiting time until the formation of the material layer on top of the solidified layer begins.

136. In the calculation method described in claim 130, The above-mentioned molding conditions are further calculated using a method that includes the oscillation mode of the energy rays.

137. In the calculation method described in claim 136, The oscillation mode includes a calculation method that includes continuous oscillation or pulse oscillation.

138. In the calculation method described in claim 130, The molding conditions further include support conditions related to the support portion that supports the unmelted material layer and the solidified layer, The support condition is a calculation method that includes the temperature of the support.

139. In the calculation method described in claim 130, The molding conditions further include design data related to the shape of the solidified layer or the three-dimensional molded object. The design data includes a calculation method that includes shape data of the solidified layer or the support portion that supports the three-dimensional object.

140. In the calculation method according to any one of claims 130 to 139, The molding conditions are further calculated using a method that includes conditions related to the atmosphere inside the enclosure in which the irradiation of the energy rays melts at least a portion of the unmelted material layer.

141. In the calculation method according to any one of claims 130 to 139, A calculation method further comprising an output unit that outputs the state of the shape of the detected unmelted material layer.

142. To acquire image data of an unmelted material layer consisting of material powder, In the calculation method according to any one of claims 130 to 141, the shape of the unmelted material layer is obtained based on the acquired image data, A detection method comprising detecting the state of the shape of the unmelted material layer.

143. In the detection method according to claim 142, Projecting light with a predetermined intensity distribution onto the aforementioned unmelted material layer, To acquire image data of at least a portion of the area on which the light is projected in the unmelted material layer, A detection system comprising: obtaining the shape of the unmelted material layer based on the acquired image data, and detecting the state of the shape of the unmelted material layer.

144. A method of shaping, Setting the molding conditions of the molding apparatus based on information relating to at least one of the flatness, density, and layer thickness of the unmelted material layer output by the calculation method described in any one of claims 130 to 141, A fabrication method comprising forming a layered unmelted material layer consisting of unmelted powder material based on the fabrication conditions, and fabricating a three-dimensional object from a solidified layer formed by solidifying at least a portion of the unmelted material layer by irradiation with energy rays.

145. A method of shaping, Setting the molding conditions of the molding apparatus based on information relating to at least one of the flatness, density, and layer thickness of the unmelted material layer output by the detection method according to claim 142 or 143, A fabrication method comprising forming a layered unmelted material layer consisting of unmelted powder material based on the fabrication conditions, and fabricating a three-dimensional object from a solidified layer formed by solidifying at least a portion of the unmelted material layer by irradiation with energy rays.

146. A computer read medium recording a arithmetic processing program that causes a computer to perform the processing in the arithmetic method described in any one of claims 130 to 141.

147. A computer read medium recording a detection processing program that causes a computer to perform the processing in the detection method described in claim 142 or 143.

148. A computer-readable medium recording a molding process program that causes a computer to execute the processing in the molding method described in claim 144 or 145.

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