Additive manufacturing apparatus

Abstract

To provide an additive manufacturing apparatus capable of additively manufacturing a high quality additive manufacturing object.SOLUTION: A controller 130 for an additive manufacturing apparatus 100 corrects an irradiation condition of a meting light beam and a heat retention light beam on the basis of a measured temperature T in a heat retention light irradiation area of the heat retention light beam KBM measured by a temperature measurement device 140. Thereby, a heat gain to a modeling surface B1 of a base material B can be controlled within a certain range, which enables additively manufacturing a high-quality additive manufacturing object FF (a plurality of beads N).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an additive manufacturing apparatus.

Background Art

[0002] It is known that additive manufacturing includes, for example, a Directed Energy Deposition method, a Powder Bed Fusion method, and the like. The Directed Energy Deposition method performs additive manufacturing by controlling the position of a processing head that irradiates a light beam (such as a laser beam and an electron beam) and supplies a material. The Directed Energy Deposition method includes LMD (Laser Metal Deposition), DMP (Direct Metal Printing), and the like. The Powder Bed Fusion method performs additive manufacturing by irradiating a light beam onto a powder material spread flat. The Powder Bed Fusion method includes SLM (Selective Laser Melting), EBM (Electron Beam Melting), and the like.

[0003] For example, LMD of the Directed Energy Deposition method can melt and then solidify powder materials and the like by irradiating a light beam while injecting a powder material containing a hard material. Thereby, LMD is used, for example, as a build-up technology for adding an additive made of a hard material partially to a shaping surface.

[0004] And, for example, Patent Document 1 and Patent Document 2 disclose an additive manufacturing apparatus of the Directed Energy Deposition method. In a conventional additive manufacturing apparatus, an additive is formed while measuring the state of a molten pool formed by melting the supplied material.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] By the way, in additive manufacturing, if the amount of heat input due to the irradiation of the light beam becomes excessive, the wetting spread of the melted material, that is, the melt pool, is likely to occur. As a result, the quality of the formed additive product may deteriorate. Therefore, in additive manufacturing, it is important to control the amount of heat input due to the irradiation of the light beam.

[0007] An object of the present invention is to provide an additive manufacturing apparatus capable of additive manufacturing a high-quality additive product. [Means for Solving the Problems]

[0008] A first aspect of the present invention is an additive manufacturing apparatus for additively manufacturing an additive product containing a hard material on a shaped surface of a base material, a powder material supply device that injects and supplies a powder material containing tungsten carbide (WC) as the hard material and cobalt (Co) or nickel (Ni) as a cemented carbide binder to the shaped surface; a melting light beam irradiation device that irradiates a melting light beam for heating and melting the supplied powder material to a temperature equal to or higher than the melting point of the powder material; a heat preservation light beam irradiation device that irradiates a heat preservation light beam for heating and keeping warm an additive product formed by solidifying the powder material melted by the irradiation of the melting light beam outside a melting light irradiation range that is an irradiation range irradiated with the melting light beam to a temperature lower than the melting point; a temperature measurement device that measures a temperature outside the melting light irradiation range in a heat preservation light irradiation range that is an irradiation range irradiated with the heat preservation light beam; a control device that independently controls each of the melting light beam irradiation device and the heat preservation light beam irradiation device with respect to the irradiation of the melting light beam and the heat preservation light beam, and the relative scanning of the melting light beam and the heat preservation light beam; and the control device controls the melting light beam irradiation device and the heat preservation light beam irradiation device so as to irradiate the melting light beam and the heat preservation light beam in a state where the heat preservation light irradiation range overlaps the melting light irradiation range while injecting the powder material toward the shaped surface by the powder material supply device, corrects irradiation conditions of the melting light beam irradiated by the melting light beam irradiation device and the heat preservation light beam irradiated by the heat preservation light beam irradiation device based on the temperature measured by the temperature measurement device, the irradiation conditions being a beam output or a spot diameter as a control element of a power density representing an output per unit area of each of the melting light beam and the heat preservation light beam, wherein the control device corrects the irradiation conditions so as to decrease the power density of the heat preservation light beam and increase the power density of the melting light beam in accordance with the decrease in the power density of the heat preservation light beam when the temperature measured by the temperature measurement device is equal to or higher than a preset reference temperature, in the additive manufacturing apparatus. A second aspect of the present invention is an additive manufacturing apparatus for additively manufacturing an additive product containing a hard material on a shaped surface of a base material, A powder material supply device that injects and supplies a powder material containing tungsten carbide (WC) as the hard material and cobalt (Co) or nickel (Ni) as the cemented carbide binder to the shaping surface; A melting light beam irradiation device that irradiates a melting light beam that heats and melts the supplied powder material to a temperature equal to or higher than the melting point of the powder material; A heat preservation light beam irradiation device that irradiates a heat preservation light beam that heats and keeps warm an additional product formed by solidifying the powder material melted by the irradiation of the melting light beam outside the melting light irradiation range that is the irradiation range irradiated with the melting light beam to a temperature below the melting point; A temperature measurement device that measures the temperature outside the melting light irradiation range in the heat preservation light irradiation range that is the irradiation range irradiated with the heat preservation light beam; A control device that independently controls each of the melting light beam irradiation device and the heat preservation light beam irradiation device with respect to the irradiation of the melting light beam and the heat preservation light beam, and the relative scanning of the melting light beam and the heat preservation light beam; The control device is configured to: Control the melting light beam irradiation device and the heat preservation light beam irradiation device so that the melting light beam and the heat preservation light beam are irradiated in a state where the heat preservation light irradiation range overlaps the melting light irradiation range while the powder material is being injected toward the shaping surface by the powder material supply device; Correct the irradiation conditions of the melting light beam irradiated by the melting light beam irradiation device and the heat preservation light beam irradiated by the heat preservation light beam irradiation device based on the temperature measured by the temperature measurement device; The irradiation conditions are the beam output or the spot diameter as a control element of the power density representing the output per unit area of each of the melting light beam and the heat preservation light beam; In the additive manufacturing apparatus, when the temperature measured by the temperature measurement device is equal to or higher than a preset reference temperature and the amount of change in the temperature over time is equal to or less than a predetermined amount of change, the control device corrects the irradiation conditions so as to decrease the power density of the heat preservation light beam and increase the power density of the melting light beam in response to the decrease in the power density of the heat preservation light beam. A third aspect of the present invention is: An additive manufacturing apparatus that adds and manufactures an additional product containing a hard material on a shaping surface of a base material, A powder material supply device that injects and supplies a powder material containing tungsten carbide (WC) as the hard material and cobalt (Co) or nickel (Ni) as the cemented carbide binder to the shaping surface; A melting light beam irradiation device that irradiates a melting light beam that heats and melts the supplied powder material to a temperature equal to or higher than the melting point of the powder material; A heat preservation light beam irradiation device that irradiates a heat preservation light beam that heats and keeps warm an additional product formed by solidifying the powder material melted by the irradiation of the melting light beam outside the melting light irradiation range that is the irradiation range irradiated with the melting light beam to a temperature lower than the melting point; A temperature measurement device that measures the temperature outside the melting light irradiation range in the heat preservation light irradiation range that is the irradiation range irradiated with the heat preservation light beam; A control device that independently controls each of the melting light beam irradiation device and the heat preservation light beam irradiation device regarding the irradiation of the melting light beam and the heat preservation light beam, and the relative scanning of the melting light beam and the heat preservation light beam; The control device: Controls the melting light beam irradiation device and the heat preservation light beam irradiation device so that while the powder material is being injected toward the shaping surface by the powder material supply device, the melting light beam and the heat preservation light beam are irradiated in a state where the heat preservation light irradiation range overlaps the melting light irradiation range; Corrects the irradiation conditions of the melting light beam irradiated by the melting light beam irradiation device and the heat preservation light beam irradiated by the heat preservation light beam irradiation device based on the temperature measured by the temperature measurement device; The irradiation conditions are the scanning speeds as control elements when scanning the melting light beam and the heat preservation light beam respectively; In the additive manufacturing device, the control device corrects the irradiation conditions so that when the temperature measured by the temperature measurement device is equal to or higher than a reference temperature, the scanning speeds of the melting light beam and the heat preservation light beam are increased to be equal to or higher than a reference scanning speed.

[0009] According to this, the thermometer can measure the temperature of the range including the heat preservation light irradiation range irradiated with the heat preservation light beam, and the control device can correct the irradiation conditions of the melting light beam and the heat preservation light beam based on the measured temperature. Thereby, the amount of heat input by the irradiation of the melting light beam and the heat preservation light beam can be managed. Therefore, the additive manufacturing apparatus can additively manufacture a high-quality additive manufactured object.

Brief Description of the Drawings

[0010]

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Embodiments for Carrying Out the Invention

[0011] (1. Overview of the Additive Manufacturing Apparatus) The additive manufacturing apparatus of this example adopts, for example, the directed energy deposition method and the LMD method. In this example, the additive manufacturing apparatus irradiates a light beam while injecting a powder material in which a binder powder material is mixed with a hard powder material, which is a hard material, toward the shaping surface of a substrate, thereby additively manufacturing a hard additive product on the shaping surface. The powder material, particularly, the hard powder material and the substrate may be different materials or the same type of material. Further, the powder material may be a granulated powder in which the hard powder material and the binder powder material are solidified.

[0012] In this example, a case will be described where a hard additive product formed using a hard powder material such as tungsten carbide (WC), which is a hard material, is additively manufactured onto a base material formed using carbon steel (S45C). In this example, as the binding powder material, cobalt (Co) that acts as a cemented carbide binder for binding tungsten carbide (WC) is used. Here, the melting point (solidification point) of tungsten carbide (WC) is 2870°C, which is higher than the melting point (solidification point) of 1495°C of cobalt (Co), which is the cemented carbide binder. Incidentally, in this example, cobalt (Co) is used as the cemented carbide binder. However, the cemented carbide binder is not limited to cobalt (Co), and for example, nickel (Ni) can also be used as the cemented carbide binder.

[0013] (2. Configuration of Additive Manufacturing Apparatus 100) As shown in FIG. 1, the additive manufacturing apparatus 100 mainly includes a powder material supply device 110, a light beam irradiation device 120, and a control device 130. Incidentally, the basic configuration and operation of the additive manufacturing apparatus 100 in this example are equivalent to those of a well-known LMD type additive manufacturing apparatus. Therefore, the description of the detailed configuration and operation of the additive manufacturing apparatus 100 will be omitted.

[0014] The powder material supply device 110 includes a hopper 111, a valve 112, a gas cylinder 113, and an injection nozzle 114. The hopper 111 stores the hard powder material P1 mixed with the binding powder material P2. Incidentally, in the following description, the powder material obtained by mixing the hard powder material P1 and the binding powder material P2 is referred to as "powder material P".

[0015] The valve 112 includes a powder introduction valve 112a, a powder supply valve 112b, and a gas introduction valve 112c. The powder introduction valve 112a is connected to the hopper 111 via a pipe 111a. The powder supply valve 112b is connected to the injection nozzle 114 via a pipe 114a. The gas introduction valve 112c is connected to the gas cylinder 113 via a pipe 113a.

[0016] The injection nozzle 114 and the pipe 114a are accommodated in a cylindrical container 115 having an inclined portion on the injection nozzle 114 side. The injection nozzle 114 is disposed at the tip of the inclined portion of the container 115. Then, the injection nozzle 114 injects the powder material P toward the shaping surface B1 of the base material B, more specifically, the additive product FF, by means of high-pressure nitrogen supplied from, for example, the gas cylinder 113 via the pipe 114a. Note that the gas for injecting the powder material P is not limited to nitrogen, and may be an inert gas such as argon.

[0017] The light beam irradiation device 120 mainly includes a melting light beam irradiation device 121, a heat-preserving light beam irradiation device 122, and a moving device 123 that relatively moves each of the melting light beam irradiation device 121 and the heat-preserving light beam irradiation device 122 independently. Here, as shown in FIGS. 1 and 2, the melting light beam irradiation device 121 and the heat-preserving light beam irradiation device 122 are arranged such that the irradiation directions (optical axes) of the light beams irradiated by each of them intersect or have a torsional positional relationship by the moving device 123. That is, as shown in FIG. 3, the melting light beam irradiation device 121 and the heat-preserving light beam irradiation device 122 are arranged such that the irradiation range of the melting light beam MBM by the melting light beam irradiation device 121 and the irradiation range of the heat-preserving light beam KBM by the heat-preserving light beam irradiation device 122 overlap (overlap).

[0018] The melting light beam irradiation device 121 includes a melting light beam irradiation unit 121b that irradiates the melting light beam MBM generated and supplied by the melting light beam generation unit 121a so as to be orthogonal to the shaping surface B1 of the base material B. The melting light beam generation unit 121a is controlled by the control device 130 to generate the melting light beam MBM.

[0019] The melting light beam irradiation unit 121b is disposed inside the container 115 in the vicinity of the injection nozzle 114. Specifically, the melting light beam irradiation unit 121b is disposed at the tip of the inclined portion of the container 115 so that the melting light beam MBM can be irradiated toward the supply position of the powder material P ejected from the injection nozzle 114.

[0020] The melting light beam MBM is irradiated through an optical system such as a collimator lens and a condenser lens (not shown) disposed inside the container 115. Then, as shown in FIG. 1, the melting light beam MBM forms a melting pool MP by melting the powder material P supplied from the powder material supply device 110 on the shaping surface B1 of the base material B. Note that the "processing head" is configured to include the injection nozzle 114, the melting light beam irradiation device 121, and the container 115, so that the powder material P and the melting light beam MBM move integrally.

[0021] The heat-preserving light beam irradiation device 122 includes a heat-preserving light beam irradiation unit 122b that irradiates the heat-preserving light beam KBM generated and supplied by the heat-preserving light beam generation unit 122a onto the shaping surface B1 of the base material B. The heat-preserving light beam irradiation device 122 is arranged such that the irradiation direction (optical axis) of the heat-preserving light beam KBM has an inclination with respect to the irradiation direction (optical axis) of the melting light beam MBM by the melting light beam irradiation device 121. The heat-preserving light beam irradiation device 122 heats and keeps warm the additional product FF (bead N described later) including the shaping surface B1 (base material B) and the melting pool MP formed on the shaping surface B1.

[0022] The heat-preserving light beam generation unit 122a is controlled by the control device 130 to generate the heat-preserving light beam KBM. The heat-preserving light beam irradiation unit 122b is disposed at the tip of the cylindrical container 122c facing the shaping surface B1 of the base material B. Specifically, the heat-preserving light beam irradiation unit 122b is disposed at the tip of the container 122c so that the heat-preserving light beam KBM can be irradiated overlapping the irradiation range of the melting light beam MBM irradiated from the melting light beam irradiation device 121. Further, the heat-preserving light beam irradiation unit 122b is disposed at the tip of the container 122c so that the heat-preserving light beam KBM can be irradiated toward the front side and the rear side, particularly at least toward the rear side of the melting pool MP, in the scanning direction of the melting light beam irradiation device 121 with respect to the formed melting pool MP and the bead N (additional product FF) formed by solidification of the melting pool MP.

[0023] The heat-insulating light beam KBM is irradiated through an optical system such as a collimator lens and a condenser lens (not shown) disposed inside the container 122c. Then, the heat-insulating light beam KBM preheats (heats) the shaping surface B1 of the base material B and the supplied unfused powder material P. Further, the heat-insulating light beam KBM keeps warm the molten pool MP formed by the melting light beam MBM and the bead N formed by the solidification of the molten pool MP.

[0024] As shown in FIG. 2, the moving device 123 mainly includes a first robot arm 123a and a second robot arm 123b. The first robot arm 123a supports the melting light beam irradiation device 121 (i.e., the processing head). Then, the first robot arm 123a relatively displaces the melting light beam irradiation device 121 in a state where the irradiation direction of the melting light beam MBM (i.e., the optical axis of the melting light beam MBM) is orthogonal to the shaping surface B1 of the base material B.

[0025] The second robot arm 123b supports the heat-insulating light beam irradiation device 122. Specifically, the second robot arm 123b supports the heat-insulating light beam irradiation device 122 in a posture where the irradiation direction of the heat-insulating light beam KBM (i.e., the optical axis of the heat-insulating light beam KBM) is inclined with respect to the irradiation direction of the melting light beam MBM (the optical axis of the melting light beam MBM), in other words, supports the heat-insulating light beam irradiation device 122 with respect to the shaping surface B1. Then, the second robot arm 123b relatively displaces the heat-insulating light beam irradiation device 122 with respect to the shaping surface B1 (base material B) following the melting light beam irradiation device 121.

[0026] Here, in this example, as shown in FIG. 3, the melting light beam irradiation device 121 irradiates a melting light beam MBM having a circular irradiation shape. Further, the heat-insulating light beam irradiation device 122 irradiates a heat-insulating light beam KBM having an elliptical irradiation shape that overlaps the melting light irradiation range MS of the melting light beam MBM and surrounds the outside of the melting light irradiation range MS of the melting light beam MBM (i.e., includes the melting light irradiation range MS inside). That is, the heat-insulating light irradiation range KS where the heat-insulating light beam irradiation device 122 irradiates the heat-insulating light beam KBM is wider than the melting light irradiation range MS where the melting light beam irradiation device 121 irradiates the melting light beam MBM.

[0027] As a result, the melting light beam MBM irradiated onto the melting light irradiation range MS mainly melts the powder material P on the shaping surface B1 of the base material B, thereby additive manufacturing an additive product FF composed of a plurality of beads N as shown in FIG. 1. Further, the heat-preserving light beam KBM irradiated onto the heat-preserving light irradiation range KS mainly preheats (heats) the shaping surface B1 of the base material B. Further, the heat-preserving light beam KBM irradiated onto the heat-preserving light irradiation range KS mainly keeps the temperature of the additive product FF (more specifically, the melting pool MP where the powder material P is melted) added and manufactured on the shaping surface B1 of the base material B from decreasing.

[0028] In this example, laser light is used as the melting light beam MBM and the heat-preserving light beam KBM. However, the melting light beam MBM and the heat-preserving light beam KBM are not limited to laser light, and for example, an electron beam can be used as long as it is an electromagnetic wave. Further, in this example, the elliptical heat-preserving light beam KBM (i.e., the heat-preserving light irradiation range KS) is irradiated so as to overlap the circular melting light beam MBM (i.e., the melting light irradiation range MS). However, for the irradiation shape, a rectangular shape or the like can be used and is not limited.

[0029] The control device 130 is a computer device having a CPU, a ROM, a RAM, an interface, etc. as main components. The control device 130 controls the powder supply of the powder material supply device 110. Specifically, the control device 130 controls the injection supply of the powder material P from the injection nozzle 114 toward the shaping surface B1 of the base material B by controlling the opening and closing of the powder supply valve 112b and the gas introduction valve 112c.

[0030] The control device 130 controls the operations of the light beam irradiation device 120, i.e., the melting light beam irradiation device 121, the heat preservation light beam irradiation device 122, and the moving device 123. Specifically, the control device 130 controls the operations of the melting light beam generation unit 121a of the melting light beam irradiation device 121 and the heat preservation light beam generation unit 122a of the heat preservation light beam irradiation device 122, respectively. Thereby, the control device 130 independently controls the irradiation conditions of each of the melting light beam MBM and the heat preservation light beam KBM. Here, as the irradiation conditions, for example, the beam output of the heat preservation light beam KBM, the heat preservation light irradiation range KS (spot diameter) of the heat preservation light beam KBM, or the scanning speed of the heat preservation light beam KBM, which are control elements of the power density representing the output per unit area of each of the melting light beam MBM and the heat preservation light beam KBM, can be mentioned. In this case, the control device 130 changes the beam output, which is a control element, changes the sizes (spot diameters) of the melting light irradiation range MS and the heat preservation light irradiation range KS, or changes the scanning speeds of the melting light beam MBM and the heat preservation light beam KBM.

[0031] Here, as shown in FIG. 4, the control device 130 performs control to increase the intensity MBP1 in the beam profile representing the distribution shape of the intensity of the melting light beam MBM compared to the intensity KBP1 in the beam profile of the heat preservation light beam KBM. The beam output of the melting light beam MBM is controlled to be a temperature at which a part of the shaping surface B1 (substrate B), the hard powder material P1, and the binding powder material P2 can be melted to form a melting pool MP. Also, the beam output of the heat preservation light beam KBM is controlled to be a reference temperature at which the shaping surface B1 (substrate B), the hard powder material P1, and the binding powder material P2 are not melted.

[0032] Further, the control device 130 operates the first robot arm 123a and the second robot arm 123b of the moving device 123 to scan the melting light beam MBM and cause the heat-retaining light beam KBM to follow the locus of the melting light beam MBM. In this case, the control device 130 can control the size of the heat-retaining light irradiation range KS and the angle of the optical axis of the heat-retaining light beam KBM with respect to the optical axis of the melting light beam MBM by operating the second robot arm 123b. Thereby, the control device 130 can control the relative posture of the heat-retaining light beam irradiation device 122 with respect to the melting light beam irradiation device 121 so that the size of the heat-retaining light irradiation range KS relative to the size of the melting light irradiation range MS becomes variable. As a result, the control device 130 can control the heating of the base material B and the powder material P by the heat-retaining light beam KBM, in other words, increase or decrease the reference temperature of the base material B and the powder material P due to the heating by the heat-retaining light beam KBM.

[0033] Furthermore, the control device 130 controls the relative scanning of the melting light beam MBM and the heat-retaining light beam KBM with respect to the shaping surface B1 of the base material B. Specifically, in this example, the control device 130 controls the rotation of the motor M1 to rotate the base material B around the central axis C and controls the rotation of the motor M2 to move the base material B in the direction of the central axis C. Thereby, the relative scanning of the melting light beam MBM and the heat-retaining light beam KBM with respect to the shaping surface B1 (that is, the circumferential surface) of the base material B is controlled.

[0034] In this example, the control device 130 rotates and moves the base material B. However, it goes without saying that the control device 130 can move the melting light beam irradiation device 121 and the heat-retaining light beam irradiation device 122 relative to the shaping surface B1 of the base material B by controlling the moving device 123.

[0035] Furthermore, the control device 130 is connected to the temperature measuring device 140. The temperature measuring device 140 is assembled to the melting light beam irradiation device 121, and measures the temperature of the bead N (additive product FF) formed on the shaping surface B1 of the base material B within the range including the heat retention light irradiation range KS, in this example, inside the heat retention light irradiation range KS. Then, the temperature measuring device 140 outputs the measured temperature T representing the measured temperature to the control device 130. Here, as the temperature measuring device 140, for example, an infrared camera, a thermograph, a radiation thermometer, or the like can be used.

[0036] (3. Outline of the additive manufacturing method of the additive product FF) Next, the additive manufacturing method of the additive product FF (bead N) will be described. In the additive manufacturing method of the additive product FF (bead N), as the first step, preheating, which is a pretreatment in the additive manufacturing process of the additive product FF (bead N), is performed by the heat retention light beam KBM.

[0037] Generally, when the temperature of the shaping surface B1 of the base material B is low, the thermal energy due to the irradiation of the melting light beam MBM easily escapes to the base material B. As a result, when the additive product FF (bead N) is additively manufactured on the shaping surface B1 of the base material B in the second step, poor forming of the bead N due to insufficient melting or the like is likely to occur. Therefore, in the first step, the shaping surface B1 of the base material B is preheated (heated) using the heat retention light beam KBM.

[0038] At this time, as shown in FIG. 5, the heat retention light irradiation range KS of the heat retention light beam KBM in the preheating treatment overlaps with the melting light irradiation range MS of the melting light beam MBM (intersects the optical axis of the melting light beam MBM) and irradiates up to the front heat retention light irradiation range KSF in the scanning direction SD of the melting light beam MBM. Note that the beam output of the heat retention light beam KBM in the preheating treatment is controlled so that the shaping surface B1 of the base material B and the powder material P do not melt and reach the reference temperature.

[0039] On one hand, for example, when the temperature of the shaping surface B1 of the base material B rises to a high level due to the formation of a plurality of beads N, the heat energy due to the irradiation of the melting light beam MBM and the heat preservation light beam KBM, in other words, the heat input amount is likely to become excessive. As a result, when the additional product FF (bead N) is additively manufactured on the shaping surface B1 of the base material B in the second stage, molding defects of the bead N are likely to occur, such as the bead width of the bead N expanding or the bead height fluctuating. Therefore, the preheating (heating) of the shaping surface B1 of the base material B using the heat preservation light beam KBM in the first stage is suppressed.

[0040] At this time, as the heat preservation light irradiation range KS of the heat preservation light beam KBM in the pre-treatment, it overlaps with the melting light irradiation range MS (intersects the optical axis of the melting light beam MBM). Here, the intensity of the heat preservation light beam KBM is smaller than that of the melting light beam MBM. However, when melting a part of the base material B (shaping surface B1) and the powder material P to form the bead N (additional product FF), a part of the base material B (shaping surface B1) and the powder material P are melted by the total heat input amount of the heat input amount by the melting light beam MBM and the heat input amount by the heat preservation light beam KBM.

[0041] Next, as the second stage, as shown in FIG. 6, a melting process is performed by irradiating the melting light beam MBM to melt a part of the shaping surface B1 of the base material B and the powder material P in the melting light irradiation range MS to form a melting pool MP. Also, in this melting process, in the heat preservation light irradiation range KSF in front of the melting light beam MBM in the scanning direction SD of the melting light beam MBM in the heat preservation light irradiation range KS of the heat preservation light beam KBM, a pre-treatment as a pre-treatment for the formation process of the melting pool MP is performed.

[0042] Then, as shown in FIG. 6, the molten light beam MBM is scanned in the scanning direction SD (in this example, the substrate B rotates to perform the scanning, but in FIG. 6, for the sake of convenience, it is described as if the molten light beam MBM is scanned). By expanding the molten pool MP in this way, the additive product FF (bead N) is additively manufactured. Here, the additive product FF (bead N) in this example is formed by binding tungsten carbide (WC) of the hard powder material P1 with cobalt (Co) of the binding powder material P2 that acts as a hard binder. And the additive product FF in this example is composed of a plurality of beads N formed in a strip shape along the circumferential direction of the substrate B (see FIG. 1).

[0043] Also, after melting the powder material P so as to expand the molten pool MP, the molten light beam MBM sequentially moves in the scanning direction SD. For this reason, in the heat retention light irradiation range KSB behind the molten light beam MBM in the scanning direction SD of the heat retention light irradiation range KS of the heat retention light beam KBM, a part of the heat retention light beam KBM irradiates the molten pool MP. Thereby, the heat retention light beam KBM performs a heat retention process as a post-treatment of the additive manufacturing of the additive product FF so as to prevent rapid cooling of the formed molten pool MP and suppress the occurrence of cracks or the like in the additive product FF.

[0044] By the way, as described above, when the temperature of the shaping surface B1 of the substrate B is high due to the formation of a plurality of beads N, the amount of heat input by the irradiation of the molten light beam MBM and the heat retention light beam KBM may become excessive. In this case, in order to lower the temperature on the shaping surface B1 of the substrate B and appropriately form a plurality of beads N, the control device 130 corrects the irradiation conditions when irradiating the molten light beam MBM and the heat retention light beam KBM based on the measured temperature T acquired from the temperature measuring device 140, and adjusts the amount of heat input by the irradiation of the molten light beam MBM and the heat retention light beam KBM according to the corrected irradiation conditions. Specifically, the control device 130 corrects the irradiation conditions so as to reduce the heating of the shaping surface B1 of the substrate B by the heat retention light beam KBM while surely melting the powder material P by the molten light beam MBM.

[0045] Therefore, as irradiation conditions, the control device 130 controls elements of the power density representing the output per unit area of each of the melting light beam MBM and the heat retaining light beam KBM. For example, the control device 130 reduces the intensity (beam output) of the heat retaining light beam KBM, reduces the heat retaining light irradiation range KS (spot diameter) of the heat retaining light beam KBM, or increases the scanning speed of the heat retaining light beam KBM. Further, in order to surely melt the powder material P, that is, to appropriately maintain the heat input even in a state where the heating by the heat retaining light beam KBM is reduced, as irradiation conditions, the control device 130 increases the intensity (beam output) of the melting light beam MBM. In this example, the case where the control device 130 corrects the irradiation conditions by reducing the intensity (beam output) of the heat retaining light beam KBM and increasing the intensity (beam output) of the melting light beam MBM as the temperature of the shaping surface B1 rises is illustrated.

[0046] (4. Details of the additive manufacturing method of the additive product FF) Next, details of the additive manufacturing method of the additive product FF will be described. The control device 130 starts the execution of the additive manufacturing apparatus control program shown in FIG. 7 in step S10, and in subsequent step S11, the control device 130 controls the operation of the powder material supply device 110. That is, the control device 130 controls the opening and closing of the valves 112 of the powder material supply device 110, specifically, the powder supply valve 112b and the gas introduction valve 112c, and when supplying the powder material P in a preset supply amount to the base material B, executes the step process of step S12.

[0047] In step S12, the control device 130 operates the melting light beam irradiation device 121 and the heat retaining light beam irradiation device 122 of the light beam irradiation device 120 according to preset initial irradiation conditions or corrected irradiation conditions as described later. Then, the control device 130 irradiates the powder material P supplied to the base material B in step S11 with the melting light beam MBM and the heat retaining light beam KBM, and adds and manufactures the bead N, that is, the additive product FF, to the shaping surface B1 of the base material B.

[0048] In step S13, the control device 130 acquires the measured temperature T of the bead N measured by the temperature measuring device 140. Here, in this example, as shown in FIG. 8, the temperature measuring device 140 measures the temperature of the bead N at the measurement position SP inside the heat insulation light irradiation range KS irradiated with the heat insulation light beam KBM, more specifically, in the rear heat insulation light irradiation range KSB, and outputs the measured temperature T to the control device 130. Then, the control device 130 executes the step process of step S14.

[0049] In this example, the temperature measuring device 140 measures the measured temperature T at at least one measurement position SP corresponding to the formed bead N. However, the temperature measuring device 140 can measure the measured temperature T at a plurality of measurement positions SP. Therefore, it is also possible for the control device 130 to acquire the measured temperature T corresponding to the bead N, for example, the measured temperature T of the melting pool MP or the measured temperature T of the shaping surface B1 of the base material B. Further, when measuring the measured temperature T, it is not limited to the measurement position SP strictly existing inside the heat insulation light irradiation range KS, and it is also possible to measure the measured temperature of the measurement position in a region where the correlation with the inside of the heat insulation light irradiation range KS is strong even outside the heat insulation light irradiation range KS (for example, a range including the heat insulation light irradiation range KS and very close to the heat insulation light irradiation range KS).

[0050] In step S14, the control device 130 determines whether or not the additive manufacturing of the bead N (additive product FF) with respect to the shaping surface B1 of the base material B is completed. That is, if the additive manufacturing of the bead N (additive product FF) with respect to the shaping surface B1 of the base material B is completed, the control device 130 determines "Yes" and ends the execution of the additive manufacturing apparatus control program by executing the step process of step S17. On the other hand, if the additive manufacturing of the bead N (additive product FF) with respect to the shaping surface B1 of the base material B is not completed, the control device 130 determines "No" and executes the step process of step S15.

[0051] In step S15, the control device 130 determines whether the measured temperature T acquired in step S13 is equal to or higher than a preset reference temperature Tb. Here, the reference temperature Tb is experimentally determined as a temperature at which, when forming the bead N (additive product FF) on the shaping surface B1 of the base material B, the spread of the bead width of the bead N due to excessive expansion of the melting pool MP is small, and cracks due to rapid cooling of the formed bead N do not occur.

[0052] Here, when forming the bead N (additive product FF), as shown in FIG. 8, focusing on the processing point Pk on the shaping surface B1 of the base material B, in the scanning direction SD, the processing point Pk is first covered by the preheating light irradiation range KSF in front of the preheating light beam KBM and preheated. Subsequently, the processing point Pk is covered by the melting light irradiation range MS of the melting light beam MBM, and a part of the processing point Pk, that is, the shaping surface B1 of the base material B, is melted by the melting light beam MBM, and the supplied powder material P is melted to form a melting pool MP. Thereafter, the processing point Pk, that is, the formed melting pool MP, is covered by the preheating light irradiation range KSB behind the preheating light beam KBM and kept warm.

[0053] Accordingly, as shown in FIG. 9, the temperature at the processing point Pk changes with the passage of time, in other words, with the approach of the melting light beam MBM and the preheating light beam KBM. That is, with the start of additive manufacturing, the temperature gradually increases (by preheating) due to the irradiation of the preheating light beam KBM in the preheating light irradiation range KSF in front. Then, with the passage of time, the temperature increases to a maximum value (for example, the melting point of the hard material) due to the irradiation of the melting light beam MBM in the melting light irradiation range MS. Thereafter, rapid cooling at the processing point Pk is suppressed by the irradiation of the preheating light beam KBM in the preheating light irradiation range KSB behind (by keeping warm).

[0054] Incidentally, on the shaping surface B1 of the base material B, a plurality of beads N are formed, and finally the additive product FF is formed. Usually, as shown in FIGS. 10 and 11, a plurality of beads N are formed by the current additive manufacturing so as to be adjacent to the bead N-1 already formed by the previous additive manufacturing. In this case, when forming the current bead N, heat accumulation occurs on the shaping surface B1 of the base material B for forming the current bead N due to the amount of heat input by the melting light beam MBM and the heat retention light beam KBM during the formation of the previous bead N-1.

[0055] When heat accumulation occurs on the shaping surface B1 of the base material B, on the shaping surface B1 of the base material B, in addition to the amount of heat input (thermal energy) by the melting light beam MBM and the heat retention light beam KBM for forming the current bead N, the amount of heat input (thermal energy) due to heat accumulation is added. In this case, for example, in a situation where the number of formed beads N is relatively small, as shown by the solid line in FIG. 9, the measured temperature T measured at the measurement position SP is less than the reference temperature Tb. That is, in this case, even if the amount of heat input (thermal energy) due to heat accumulation is added to the amount of heat input (thermal energy) by the melting light beam MBM and the heat retention light beam KBM, the amount of heat input (thermal energy) does not become excessive.

[0056] On the other hand, for example, as the number of formed beads N increases, the heat accumulation on the shaping surface B1 of the base material B increases. Therefore, as shown by the broken line in FIG. 9, the measured temperature T measured at the measurement position SP becomes equal to or higher than the reference temperature Tb. That is, in this case, the amount of heat input (thermal energy) becomes excessive by adding the amount of heat input (thermal energy) due to heat accumulation to the amount of heat input (thermal energy) by the melting light beam MBM and the heat retention light beam KBM.

[0057] Therefore, when the melting light beam MBM and the heat-retaining light beam KBM are repeatedly irradiated under the same irradiation conditions as when the previous bead N-1 was formed, in a situation where the number of formed beads N is small, the heat input (thermal energy) does not become excessive. As a result, when the measured temperature T is less than the reference temperature Tb, as shown in FIG. 10, the formed bead N has a stable bead width W (in other words, there is no spread in the bead width W), and rapid cooling of the melting pool MP is suppressed and cracking does not occur. On the other hand, in a situation where the number of formed beads N increases, the heat input (thermal energy) becomes excessive. As a result, when the measured temperature T is equal to or higher than the reference temperature Tb, as shown in FIG. 11, the melting pool MP expands excessively with the excessive heat input during the formation of the bead N. Therefore, the formed bead N has an unstable bead width W because the bead width W is likely to spread.

[0058] Therefore, when the measured temperature T is equal to or higher than the reference temperature Tb, the control device 130 determines "Yes" in step S15 and executes the step process of step S16 in order to correct the irradiation conditions of the light beam irradiation device 120. On the other hand, when the measured temperature T is less than the reference temperature Tb, the control device 130 determines "No" in step S15 because there is no need to correct the irradiation conditions of the light beam irradiation device 120. Then, the control device 130 executes each step process after step S12.

[0059] As described above, when the measured temperature T becomes equal to or higher than the reference temperature Tb, in addition to the formation of the melting pool MP by the melting light beam MBM, the temperature of the base material B increases due to the preheating process and the heat-retaining process by the heat-retaining light beam KBM. That is, when the measured temperature T becomes equal to or higher than the reference temperature Tb, the heat input (thermal energy) when the melting light beam MBM and the heat-retaining light beam KBM are irradiated becomes excessive. And in a state where the heat input (thermal energy) is excessive, the bead width tends to spread.

[0060] Therefore, when the control device 130 determines in the step process of step S15 that the measured temperature T is equal to or higher than the reference temperature Tb, it corrects and adjusts the irradiation conditions of the light beam irradiation device 120 in step S16. Hereinafter, the correction of the irradiation conditions in step S16 will be specifically described.

[0061] When the measured temperature T becomes equal to or higher than the reference temperature Tb, as described above, the main factor is the excessive heat input amount (thermal energy) by the light beam irradiation device 120. More specifically, since the melting light beam MBM by the melting light beam irradiation device 121 needs to melt a part of the shaping surface B1 of the base material B and the powder material P, the main factor is the excessive heat input amount (thermal energy) of the heat preservation light beam KBM irradiated by the heat preservation light beam irradiation device 122.

[0062] Therefore, in step S16, the control device 130 corrects and adjusts the irradiation conditions so as to reduce the heat input amount (thermal energy) used for preheating the shaping surface B1 of the base material B and maintaining the formed melting pool MP. Specifically, the control device 130 reduces the intensity of the heat preservation light beam KBM as the irradiation condition in order to reduce the heat input amount (thermal energy).

[0063] In addition, in step S sixteen, the control device 130 increases the intensity of the melting light beam MBM in response to the decrease in the intensity of the heat preservation light beam KBM in order to compensate for the decrease in the heat input amount (thermal energy) required for forming a part of the shaping surface B1 of the base material B and the powder material P, that is, the melting pool MP, along with the decrease in the intensity of the heat preservation light beam KBM. In this case, as shown in FIG. , the control device 130 reduces the intensity KBP1 of the heat preservation light beam KBM and increases the intensity MBP1 of the melting light beam MBM in the beam profile. Note that the increase in the intensity of the melting light beam MBM can be performed as necessary.

[0064] Alternatively, in step S16, in order to reduce the amount of heat input (thermal energy) used for preheating the shaping surface B1 of the base material B and maintaining the formed molten pool MP, as irradiation conditions, the control device 130 operates the second robot arm 123b of the moving device 123 to reduce the heat retention light irradiation range KS, particularly the front heat retention light irradiation range KSF. In this case, the control device 130 operates the second robot arm 123b to, for example, reduce the inclination (reduce the angle) of the optical axis of the heat retention light beam KBM with respect to the optical axis of the melting light beam MBM. Thereby, the heat retention light irradiation range KS can be reduced.

[0065] Still, also in this case, the control device 130 maintains the molten pool MP by the heat retention light irradiation range KSB behind the heat retention light beam KBM. Thereby, it is possible to suppress the rapid cooling of the formed molten pool MP and prevent the occurrence of cracks in the formed bead N (additive product FF).

[0066] Alternatively, in step S16, in order to reduce the amount of heat input (thermal energy) to the shaping surface B1 of the base material B by the melting light beam MBM and the heat retention light beam KBM, as irradiation conditions, the control device 130 operates the first robot arm 123a and the second robot arm 123b of the moving device 123 to increase the scanning speed of the melting light beam MBM and the heat retention light beam KBM with respect to the shaping surface B1 of the base material B. Thereby, the amount of heat input (thermal energy) to the shaping surface B1 of the base material B by the irradiation of the melting light beam MBM and the heat retention light beam KBM can be relatively reduced, that is, the heat accumulation on the shaping surface B1 of the base material B can be relatively reduced.

[0067] The control device 130 corrects and adjusts the irradiation conditions of the light beam irradiation device 120 according to the measured temperature T, in other words, according to the amount of heat input to the shaping surface B1 of the base material B, and then executes each step process after step S12. Then, the control device 130 executes the additive manufacturing apparatus control program until it determines "Yes" in step S14, that is, until the additive manufacturing is completed.

[0068] As can be understood from the above description, according to the additive manufacturing apparatus 100, the thermometer 140 measures the temperature inside the heat insulation light irradiation range KS irradiated with the heat insulation light beam KBM, and the control device 130 corrects the irradiation conditions of the melting light beam MBM and the heat insulation light beam KBM with respect to the shaping surface B1 of the base material B based on the measured temperature T. That is, the control device 130 can feedback the heat input amount and correct the irradiation conditions by acquiring the measured temperature T from the thermometer 140. Thereby, it is possible to manage so that the heat input amount by the irradiation of the melting light beam MBM and the heat insulation light beam KBM is maintained within a certain range. Therefore, the additive manufacturing apparatus 100 can additively manufacture a high-quality additive product FF, that is, the bead N.

[0069] (5. First alternative example) In the above-described example, when the measured temperature T becomes equal to or higher than the reference temperature Tb, the irradiation conditions of the light beam irradiation device 120 are corrected and adjusted so as to reduce the intensity of the heat insulation light beam KBM. By the way, for example, when forming an additive product FF by forming a large number of beads N, even if the intensity of the heat insulation light beam KBM is reduced due to the progress of heat storage of the base material B, there may be a situation where the measured temperature T is difficult to drop below the reference temperature Tb early.

[0070] Therefore, in the first alternative example, as shown in FIG. 13, the light beam irradiation device 120 includes a cooling device 124. The cooling device 124 is attached to the heat insulation light beam irradiation device 122. Then, under the control of the control device 130, the cooling device 124 injects, for example, low-temperature cooling air CW, which is an inert gas such as nitrogen (N2) or argon (Ar), toward the shaping surface B1 of the base material B. In the first alternative example, the case where the cooling device 124 is attached to the heat insulation light beam irradiation device 122 is illustrated. However, the cooling device 124 can also be attached to the melting light beam irradiation device 121 or provided independently of the melting light beam irradiation device 121 and the heat insulation light beam irradiation device 122.

[0071] Also in the first alternative example, similar to the additive manufacturing method of the additive product FF described in the present example above, the control device 130 executes the additive manufacturing apparatus control program of FIG. 7. However, in the first alternative example, the step process of step S16 of the additive manufacturing apparatus control program is slightly changed. That is, in the first alternative example, at step S16, the control device 130 reduces the intensity of the heat retention light beam KBM as irradiation conditions and operates the cooling device 124 to inject cooling air CW toward the shaping surface B1 of the base material B in order to reduce the heat input amount (thermal energy).

[0072] In this case, it is desirable that the cooling device 124 injects the cooling air CW mainly toward the front heat retention light irradiation range KSF in the heat retention light irradiation range KS. Thereby, while suppressing the rapid cooling of the formed molten pool MP, it is possible to suppress the heat storage on the shaping surface B1 of the base material B, and the measured temperature T can be cooled to less than the reference temperature Tb. That is, by suppressing the heat storage on the shaping surface B1 of the base material B, the heat input amount of the melting light beam MBM and the heat retention light beam KBM to the shaping surface B1 of the base material B can be relatively reduced. Therefore, also in the first alternative example, the same effect as that of the present example described above can be obtained.

[0073] (6. Others) In the present example and the first alternative example described above, the control device 130 corrects and adjusts the irradiation conditions of the light beam irradiation device 120 when the measured temperature T is equal to or higher than the reference temperature Tb. By the way, when the shaping surface B1 of the base material B stores heat, the change amount T(t) representing the temporal change of the measured temperature T tends to become small. Therefore, the control device 130 can also correct the irradiation conditions of the light beam irradiation device 120 when the change amount T(t) is equal to or less than a preset reference change amount Tb(t), that is, when the shaping surface B1 of the base material B stores heat and the temperature decrease is gentle.

[0074] Specifically, in step S15 of the above-described additive manufacturing apparatus control program, the control device 130 determines whether or not the change amount T(t) is less than or equal to the reference change amount Tb(t) in addition to the above-described step processing. Then, when the measured temperature T is equal to or higher than the reference temperature Tb and the change amount T(t) is less than or equal to the reference change amount Tb(t), for example, the control device 130 decreases the intensity of the heat-insulating light beam KBM while increasing the intensity of the melting light beam MBM, or increases the scanning speed V of the melting light beam MBM and the heat-insulating light beam KBM to be higher than the reference scanning speed Vb. Thereby, similar to the above-described present example, the heat input amount to the shaping surface B1 of the base material B can be decreased, and a high-quality additive manufactured object FF can be additively manufactured.

[0075] Alternatively, the control device 130 operates the cooling device 124 to inject cooling air CW toward the shaping surface B1 of the base material B. Thereby, similar to the above-described first alternative example, by suppressing the heat storage on the shaping surface B1 of the base material B, the heat input amount of the melting light beam MBM and the heat-insulating light beam KBM to the shaping surface B1 of the base material B can be relatively reduced, and the same effect as the above-described present example can be obtained.

[0076] Also, in the above-described present example and the first alternative example, in the additive manufacturing apparatus 100, the powder material supply device 110 injects and supplies a powder material P composed of a hard powder material P1 and a binding powder material P2 to the shaping surface B1 of the base material B. However, the material supply to the shaping surface B1 is not limited to the powder material P, and it is also possible to supply, for example, a wire or the like made of a metal linear material by a material supply device. In this case, the supplied linear material is melted by the melting light beam MBM irradiated from the light beam irradiation device 120 and heat-insulated by the heat-insulating light beam KBM. Then, by correcting the irradiation conditions so as to obtain an appropriate heat input amount (thermal energy), an additive manufactured object FF can be additively manufactured on the shaping surface B1 of the base material B. Therefore, the same effect as the above-described present example and the first alternative example can be expected.

[0077] Furthermore, in the above-described example and the like, the case where the additive manufacturing apparatus 100 adopts the LMD method has been described. Instead of this, even when the additive manufacturing apparatus adopts the SLM method, the additive manufactured object FF can be additively manufactured by correcting the irradiation conditions of the light beam so as to obtain an appropriate heat input amount (thermal energy). However, when the SLM method is adopted, usually, the scanning speed of the light beam is faster than the scanning speed of the light beam in the LMD method. For this reason, when the additive manufacturing apparatus adopts the SLM method, for example, it is preferable to reduce the scanning speed of the melting light beam and the heat preservation light beam as compared with the normal additive manufacturing. The more the scanning speed is reduced, the easier it is to correct the irradiation conditions so as to obtain an appropriate heat input amount (thermal energy), and a high-quality additive manufactured object FF can be additively manufactured.

Explanation of Signs

[0078] 100... Additive manufacturing apparatus, 110... Powder material supply apparatus, 111... Hopper, 111a... Pipe, 112... Valve, 112a... Powder introduction valve, 112b... Powder supply valve, 112c... Gas introduction valve, 113... Gas cylinder, 113a... Pipe, 114... Injection nozzle, 114a... Pipe, 115... Container, 120... Light beam irradiation apparatus, 121... Melting light beam irradiation apparatus, 121a... Melting light beam generation unit, 121b... Melting light beam irradiation unit, 122... Heat preservation light beam irradiation apparatus, 122a... Heat preservation light beam generation unit, 122b... Heat preservation light beam irradiation unit, 122c... Container, 123... Moving apparatus, 123a... First robot arm, 123b... Second robot arm, 130... Control apparatus, 140... Temperature measurement apparatus, B... Base material, B1... Modeling surface, C... Central axis, FF... Additive manufactured object, N... Bead, MP... Melting pool, KBM... Heat preservation light beam, MBM... Melting light beam, MS... Melting light irradiation range, KS... Heat preservation light irradiation range, KSB... Rear heat preservation light irradiation range, KSF... Front heat preservation light irradiation range, M1... Motor, M2... Motor, P... Powder material, P1... Hard powder material, P2... Binding powder material, G... Image data, SD... Scanning direction, SS... Outer light irradiation range, W... Bead width, SP... Measurement position, T... Measured temperature, Tb... Reference temperature, V... Scanning speed, Vb... Reference scanning speed, Pk... Processing point

Claims

An additive manufacturing apparatus for additively manufacturing an additive product containing a hard material on a shaped surface of a substrate, comprising: a powder material supply device that injects and supplies a powder material containing tungsten carbide (WC) as the hard material and cobalt (Co) or nickel (Ni) as a cemented carbide binder onto the shaped surface; a melting light beam irradiation device that irradiates a melting light beam for heating and melting the supplied powder material to a temperature equal to or higher than the melting point of the powder material; a heat preservation light beam irradiation device that irradiates a heat preservation light beam for heating and keeping warm an additive product formed by solidification of the powder material melted by the irradiation of the melting light beam outside a melting light irradiation range which is an irradiation range irradiated with the melting light beam to a temperature lower than the melting point; a temperature measurement device that measures the temperature outside the melting light irradiation range in a heat preservation light irradiation range which is an irradiation range irradiated with the heat preservation light beam; a control device that independently controls each of the melting light beam irradiation device and the heat preservation light beam irradiation device with respect to irradiation of the melting light beam and the heat preservation light beam, and relative scanning of the melting light beam and the heat preservation light beam; The control device is configured to: control the melting light beam irradiation device and the heat preservation light beam irradiation device to irradiate the melting light beam and the heat preservation light beam in a state where the heat preservation light irradiation range overlaps the melting light irradiation range while injecting the powder material toward the shaped surface by the powder material supply device; correct irradiation conditions of the melting light beam irradiated by the melting light beam irradiation device and the heat preservation light beam irradiated by the heat preservation light beam irradiation device based on the temperature measured by the temperature measurement device; wherein the irradiation conditions are a beam output or a spot diameter as a control element of a power density representing an output per unit area of each of the melting light beam and the heat preservation light beam; The control device corrects the irradiation conditions such that when the temperature measured by the temperature measurement device is equal to or higher than a preset reference temperature, the power density of the heat preservation light beam is decreased and the power density of the melting light beam is increased in response to the decrease in the power density of the heat preservation light beam. An additive manufacturing apparatus. An additive manufacturing apparatus for additively manufacturing an additive product containing a hard material on a shaped surface of a substrate, comprising: A powder material supply device that injects and supplies a powder material containing tungsten carbide (WC) as the hard material and cobalt (Co) or nickel (Ni) as the cemented carbide binder to the shaping surface; A molten light beam irradiation device that irradiates a molten light beam that heats and melts the supplied powder material to a temperature equal to or higher than the melting point of the powder material; A heat preservation light beam irradiation device that irradiates a heat preservation light beam that heats and keeps warm an additional product formed by solidifying the powder material melted by the irradiation of the molten light beam outside the molten light irradiation range which is the irradiation range irradiated with the molten light beam to a temperature below the melting point; A temperature measurement device that measures the temperature outside the molten light irradiation range in the heat preservation light irradiation range which is the irradiation range irradiated with the heat preservation light beam; A control device that independently controls each of the molten light beam irradiation device and the heat preservation light beam irradiation device with respect to the irradiation of the molten light beam and the heat preservation light beam, and the relative scanning of the molten light beam and the heat preservation light beam; The control device is configured to: Control the molten light beam irradiation device and the heat preservation light beam irradiation device so as to irradiate the molten light beam and the heat preservation light beam in a state where the heat preservation light irradiation range overlaps the molten light irradiation range while injecting the powder material toward the shaping surface by the powder material supply device; Correct the irradiation conditions of the molten light beam irradiated by the molten light beam irradiation device and the heat preservation light beam irradiated by the heat preservation light beam irradiation device based on the temperature measured by the temperature measurement device; The irradiation conditions are the beam output or the spot diameter as a control element of the power density representing the output per unit area of each of the molten light beam and the heat preservation light beam; The control device corrects the irradiation conditions such that when the temperature measured by the temperature measurement device is equal to or higher than a preset reference temperature and the amount of change in the temperature over time is equal to or less than a predetermined amount of change, the power density of the heat preservation light beam is decreased, and the power density of the molten light beam is increased in response to the decrease in the power density of the heat preservation light beam. An additive manufacturing apparatus.

3. An additive manufacturing apparatus for additively manufacturing an additional product containing a hard material on a shaping surface of a base material, A powder material supply device that injects and supplies a powder material containing tungsten carbide (WC) as the hard material and cobalt (Co) or nickel (Ni) as the cemented carbide binder to the shaping surface; A molten light beam irradiation device that irradiates a molten light beam that heats and melts the supplied powder material to a temperature equal to or higher than the melting point of the powder material; A heat preservation light beam irradiation device that irradiates a heat preservation light beam that heats and keeps warm an additional product formed by solidifying the powder material melted by the irradiation of the molten light beam outside the molten light irradiation range that is the irradiation range irradiated with the molten light beam to a temperature below the melting point; A temperature measurement device that measures the temperature outside the molten light irradiation range in the heat preservation light irradiation range that is the irradiation range irradiated with the heat preservation light beam; A control device that independently controls each of the molten light beam irradiation device and the heat preservation light beam irradiation device with respect to the irradiation of the molten light beam and the heat preservation light beam, and the relative scanning of the molten light beam and the heat preservation light beam; The control device is configured to: Control the molten light beam irradiation device and the heat preservation light beam irradiation device so as to irradiate the molten light beam and the heat preservation light beam in a state where the heat preservation light irradiation range overlaps the molten light irradiation range while injecting the powder material toward the shaping surface by the powder material supply device; Correct the irradiation conditions of the molten light beam irradiated by the molten light beam irradiation device and the heat preservation light beam irradiated by the heat preservation light beam irradiation device based on the temperature measured by the temperature measurement device; The irradiation conditions are the scanning speeds as control elements when scanning the molten light beam and the heat preservation light beam, respectively; The control device corrects the irradiation conditions so as to increase the scanning speeds of the molten light beam and the heat preservation light beam to a reference scanning speed or higher when the temperature measured by the temperature measurement device is equal to or higher than a reference temperature. The additive manufacturing device.

4. The control device does not correct the irradiation conditions when the temperature measured by the temperature measurement device is lower than a preset reference temperature. The additive manufacturing device according to any one of claims 1-3.

5. The control device forms a plurality of beads adjacent to each other. When the thermal energy due to heat storage in the base material when the existing bead adjacent to the newly formed predetermined bead is formed is less than a predetermined value, the temperature measured by the temperature measuring device becomes lower than the reference temperature. The additive manufacturing apparatus according to any one of claims 1 to 4, wherein when the thermal energy due to heat storage in the base material when the existing bead adjacent to the newly formed predetermined bead is formed is equal to or greater than a predetermined value, the temperature measured by the temperature measuring device becomes equal to or higher than the reference temperature.

6. The control device corrects the irradiation conditions so that the heat retention light beam retains the molten pool formed by melting the powder material with the melting light beam, according to the additive manufacturing apparatus according to any one of claims 1 to 5.

7. Furthermore, the additive manufacturing apparatus according to any one of claims 1 to 6, comprising a cooling device for cooling the heat retention light irradiation range.

8. The control device controls the posture of the heat retention light beam irradiation device in a state where the irradiation direction of the heat retention light beam is inclined with respect to the irradiation direction of the melting light beam, according to the additive manufacturing apparatus according to any one of claims 1 to 7.

9. The irradiation direction of the melting light beam is a direction perpendicular to the shaping surface for shaping the additive manufactured object, according to the additive manufacturing apparatus according to any one of claims 1 to 8.

10. The powder material supply device is provided so as to be movable integrally with the melting light beam irradiation device, according to the additive manufacturing apparatus according to any one of claims 1 to 9.

11. The control device controls the scanning of the heat retention light beam irradiated by the heat retention light beam irradiation device so as to follow the trajectory of the scanning of the melting light beam irradiated by the melting light beam irradiation device, according to the additive manufacturing apparatus according to any one of claims 1 to 10.

12. The melting point of the hard material is higher than the melting point of the cemented carbide binder, according to the additive manufacturing apparatus according to any one of claims 1 to 11.

Images