Method for monitoring the manufacturing process, additive manufacturing apparatus, and additive manufacturing method

Abstract

A monitoring method for a fabrication process according to at least one embodiment of the present disclosure comprises: a step for irradiating a layer of a raw material powder with an energy beam to fuse and solidify the raw material powder of the layer and thereby fabricate a part of a fabrication product; a first detection step for detecting the presence or absence of a defect in the fabrication product while the fabrication step is performed; and a second detection step for measuring a surface shape of the fabrication product after the fabrication step has been performed and detecting the presence of a defect in the fabrication product on the basis of the surface shape of the fabrication product. The first detection step and the second detection step are performed each time the fabrication step is performed.

Description

Technical Field

[0001] The present disclosure relates to a modeling process monitoring method, an additive manufacturing apparatus, and an additive manufacturing method. This application claims priority based on Japanese Patent Application No. 2022-178799 filed with the Japan Patent Office on November 8, 2022, the content of which is incorporated herein by reference in its entirety.

Background Art

[0002] Among additive manufacturing methods for additively manufacturing three-dimensional objects, for example, in the powder bed additive manufacturing method, a three-dimensional object (modeled object) is formed by repeatedly laminating molten and solidified layers by irradiating metal powder, which is raw material powder laid in layers, with an energy beam such as a light beam or an electron beam (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0004] In the region irradiated with the energy beam, the metal powder melts rapidly. Therefore, defects such as voids inside the modeled object may occur in the modeled object. Therefore, in order to ensure the quality of the modeled object, it is necessary to perform non-destructive inspection on the modeled object after the modeling of the modeled object is completed. However, non-destructive inspection performed after the modeling of the modeled object is completed takes time and also incurs costs.

[0005] In view of the above circumstances, at least one embodiment of the present disclosure aims to reduce the inspection time and the cost required for inspection of an additively manufactured object.

Means for Solving the Problems

[0006] (1) A method for monitoring a molding process according to at least one embodiment of the present disclosure is: A step of forming a part of an object by irradiating a layer of raw material powder with an energy beam to melt and solidify the raw material powder in the layer, A first detection step for detecting whether or not there are defects in the molded object during the molding step, A second detection step involves measuring the surface shape of the molded object after performing the molding step, and detecting the presence or absence of defects in the molded object based on the surface shape of the molded object. Equipped with, The first detection step and the second detection step are performed each time the molding step is carried out.

[0007] (2) An additive manufacturing apparatus according to at least one embodiment of the present disclosure, A powder bed forming section having a base plate on which a layer of supplied raw material powder is formed, The aforementioned layer is provided with an energy beam irradiation unit capable of irradiating it with an energy beam, A first detection device configured to detect the presence or absence of defects in the fabricated object during irradiation with the energy beam, A second detection device configured to measure the surface shape of the fabricated object after irradiating it with the energy beam and to detect the presence or absence of defects in the fabricated object based on the surface shape of the fabricated object, Equipped with, The powder bed forming unit is configured to detect the presence or absence of defects in the molded object using the first detection device, and after detecting the presence or absence of defects in the molded object using the second detection device, to supply the raw material powder and form a layer of the raw material powder.

[0008] (3) A method of additive manufacturing according to at least one embodiment of the present disclosure includes the step of detecting whether or not there are defects in the manufactured object by the manufacturing process monitoring method of (1) above, It is equipped with. [Effects of the Invention]

[0009] According to at least one embodiment of this disclosure, the inspection time and cost of inspecting additively manufactured products can be reduced. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing the overall configuration of a three-dimensional additive manufacturing apparatus to which the manufacturing process monitoring method according to at least one embodiment of this disclosure can be applied. [Figure 2] This is a flowchart showing the processing steps in the additive manufacturing method according to the first embodiment using a three-dimensional additive manufacturing apparatus. [Figure 3] This figure shows the light emission intensity and the standard deviation of the light emission intensity emitted from a test specimen when layers are sequentially formed on a test specimen containing simulated defects. [Figure 4] This graph illustrates the relationship between the depth of a defect in a fabricated object and the output of the light beam when repairing defects in the object. [Figure 5A] This diagram illustrates the scanning pattern of the light beam when repairing defects in a fabricated object. [Figure 5B] This diagram illustrates the scanning pattern of the light beam when repairing defects in a fabricated object. [Figure 5C] This diagram illustrates the scanning pattern of the light beam when repairing defects in a fabricated object. [Figure 5D] This diagram illustrates the scanning pattern of the light beam when repairing defects in a fabricated object. [Figure 5E] This diagram illustrates the scanning pattern of the light beam when repairing defects in a fabricated object. [Figure 5F] This diagram illustrates the scanning pattern of the light beam when repairing defects in a fabricated object. [Figure 5G] This diagram illustrates the scanning pattern of the light beam when repairing defects in a fabricated object. [Figure 6] This is a flowchart showing the processing steps in the additive manufacturing method according to the second embodiment using a three-dimensional additive manufacturing apparatus. [Figure 7]This is a flowchart showing the processing procedure in the additive manufacturing method according to the third embodiment using a three-dimensional additive manufacturing apparatus. [Figure 8] This is a flowchart showing the processing procedure in the additive manufacturing method according to the fourth embodiment using a three-dimensional additive manufacturing apparatus. [Figure 9] This is a schematic diagram showing the overall configuration of a three-dimensional additive manufacturing apparatus, which is an additive manufacturing apparatus to which the additive manufacturing method according to the sixth embodiment can be applied. MODES FOR CARRYING OUT THE INVENTION

[0011] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments or illustrated in the drawings are not intended to limit the scope of the present disclosure thereto, and are merely illustrative examples. For example, expressions representing relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "centered", "concentric", or "coaxial" shall not only strictly represent such an arrangement, but also represent a state of relative displacement with a tolerance or an angle and distance to the extent that the same function can be obtained. For example, expressions representing that things are in an equal state such as "identical", "equal", and "homogeneous" shall not only strictly represent an equal state, but also represent a state where there is a tolerance or a difference to the extent that the same function can be obtained. For example, expressions representing shapes such as a quadrangular shape and a cylindrical shape shall not only represent shapes such as a quadrangular shape and a cylindrical shape in a geometrically strict sense, but also represent shapes including uneven portions, chamfered portions, and the like within the range where the same effect can be obtained. On the other hand, the expressions "comprising", "equipped with", "provided with", "including", or "having" one constituent element are not exclusive expressions that exclude the presence of other constituent elements.

[0012] (Regarding Three-Dimensional Additive Manufacturing Apparatus 1) Figure 1 is a schematic diagram showing the overall configuration of a three-dimensional additive manufacturing apparatus 1 to which the manufacturing process monitoring method according to at least one embodiment of this disclosure can be applied. The three-dimensional additive manufacturing apparatus (additive manufacturing apparatus) 1 is a device for manufacturing three-dimensional objects 15 by irradiating metal powder, which is a raw material powder laid in layers, with a light beam 71 as an energy beam to perform additive manufacturing, and can perform additive manufacturing using the powder bed method. The three-dimensional additive manufacturing apparatus 1 shown in Figure 1 can, for example, form turbine blades and stator blades for gas turbines and steam turbines, or components such as the inner cylinder, tail cylinder, and nozzle of a combustor.

[0013] The three-dimensional additive manufacturing apparatus 1 shown in Figure 1 includes a storage unit 31 for raw material powder 30. The three-dimensional additive manufacturing apparatus 1 shown in Figure 1 includes a powder bed forming unit 5 having a base plate 2 on which a powder bed 8 is formed by sequentially stacking layers 8a of raw material powder 30 supplied from the storage unit 31. The three-dimensional additive manufacturing apparatus 1 shown in Figure 1 includes a light beam irradiation unit 21 capable of irradiating the powder bed 8 with a light beam 71, and a light beam irradiation device 20 including a light beam control unit 22 that controls the light beam irradiation unit 21. The three-dimensional additive manufacturing apparatus 1 shown in Figure 1 includes a powder laying unit 10 (described later), a drive cylinder 2a for the base plate 2, and a control unit 80 that controls the entire three-dimensional additive manufacturing apparatus 1. Furthermore, the three-dimensional additive manufacturing apparatus 1 shown in Figure 1 includes a first detection device 40, a second detection device 50, and a flaw detection device 60.

[0014] The base plate 2 serves as the foundation on which the object 15 is created. The base plate 2 is positioned inside a roughly cylindrical cylinder 4, which has a central axis aligned vertically, and is movable up and down by a drive cylinder 2a. During the creation process, as the base plate 2 is lowered in each cycle, a new layer 8a is formed on the upper side of the powder bed 8 on the base plate 2 by laying raw material powder 30 on the upper side.

[0015] The three-dimensional additive manufacturing apparatus 1 shown in Figure 1 includes a powder laying unit 10 for laying raw material powder 30 on a base plate 2 to form a layer 8a of raw material powder 30. The powder laying unit 10 supplies raw material powder 30 from a storage unit 31 to the upper surface of the base plate 2 and flattens its surface to form a layer 8a with substantially uniform thickness across the entire upper surface of the base plate 2. The powder bed 8, on which each layer 8a formed in each cycle is sequentially stacked, is selectively melted and solidified by irradiation with a light beam 71 from a light beam irradiation unit 21. In the next cycle, raw material powder 30 is laid again on the upper layer by the powder laying unit 10, forming a new layer 8a, and thus the layers are stacked in a layered manner.

[0016] Furthermore, the raw material powder 30 supplied from the powder laying section 10 is a powdered substance that serves as the raw material for the molded object 15, and can widely be used as a material for metals such as iron, copper, aluminum, or titanium, or for non-metals such as ceramics.

[0017] In the three-dimensional additive manufacturing apparatus 1 shown in Figure 1, the powder bed forming section 5 and the powder laying section 10 are housed within a chamber 9. The chamber 9 is provided with multiple windows 9a that allow light beams 71, light beams input and output to the second detection device 50 (described later), and light beams input and output to the flaw detection device 60 to pass through. Protective glass or the like is placed in the windows 9a to allow light beams 71 and light beams to pass through while maintaining airtightness between the inside and outside of the chamber 9.

[0018] The control unit 80 is the control unit of the three-dimensional additive manufacturing apparatus 1 shown in Figure 1, and is composed of an electronic processing unit such as a computer. The control unit 80 receives information necessary for the fabrication of the object 15, specifically information regarding the scanning position of the light beam 71 for each layer 8a. The information regarding the irradiation position of the light beam 71 for each layer 8a may be input from an external device, for example, and stored in a memory unit (not shown) of the control unit 80.

[0019] The control unit 80 is configured to control the drive of the drive cylinder 2a of the powder bed forming unit 5. The control unit 80 is also configured to control the first detection device 40, the second detection device 50, and the flaw detection device 60 in coordination.

[0020] (Light beam irradiation device 20) The light beam irradiation device 20 is a device for irradiating a powder bed 8 with a light beam 71, and as described above, it has a light beam irradiation unit 21 capable of irradiating with the light beam 71, and a light beam control unit 22 that controls the light beam irradiation unit 21. The light beam control unit 22 is configured as an electronic computing device such as a computer, and is configured to control the irradiation position of the light beam 71 irradiated by the light beam irradiation unit 21 based on information regarding the irradiation position of the light beam 71 for each layer 8a received from the control unit 80.

[0021] (First detection device 40) The first detection device 40 is a device for detecting the presence or absence of defects in the fabricated object 15 based on the light emission intensity of the light emitted from the fabricated object 15 when the light beam 71 is irradiated onto it, that is, the light emitted from the molten pool and plume formed when the light beam 71 is irradiated onto it. For example, it is a plasma emission monitor capable of detecting plasma emission during the process in real time. The first detection device 40 has a light detection unit 41 for detecting the light emitted from the fabricated object 15, and an emission monitor control unit 42 capable of detecting the presence or absence of defects in the fabricated object 15 based on the light emission intensity of the light detected by the light detection unit 41. The light emission monitor control unit 42 is configured by an electronic computing device, such as a computer. In the three-dimensional additive manufacturing apparatus 1 shown in Figure 1, when the light beam 71 is irradiated, the light emitted from the manufactured object 15 is reflected by the beam splitter 6 and incident on the light detection unit 41.

[0022] (Second detection device 50) The second detection device 50 is a shape measuring device capable of measuring the shape of the build surface area, i.e., the upper surface of the build object 15 on the base plate 2 and the surface of the powder bed 8. In some embodiments, the second detection device 50 is an optical scanner based on, for example, the fringe projection method. The second detection device 50 includes a projection unit 51, which is a projector configured to project a fringe pattern (striped pattern) onto the build surface area on the base plate 2; an imaging unit 52 configured to capture images of the fringe pattern projected onto the build surface area; and a surface irregularity detection unit 53 configured to detect irregularities in the build surface area based on image data acquired by the imaging unit 52. The unevenness detection unit 53 is configured, for example, by an electronic computing device such as a computer, and is configured to detect the presence or absence of defects in the layer 8a made of raw material powder 30 and the presence or absence of defects in the molded object 15 based on the state of unevenness in the molded surface area.

[0023] The defects in layer 8a detected by the second detection device 50 are undesirable irregularities in layer 8a. Furthermore, the defects in the fabricated object 15 detected by the second detection device 50 are undesirable deformations or opening defects on the upper surface of the fabricated object 15.

[0024] (flaw detection device 60) The flaw detection device 60 is a flaw detection device for detecting defects in the fabricated object 15, and in some embodiments, it is a flaw detection device using, for example, a laser ultrasonic method. The flaw detection device 60 includes a laser irradiation device 61 configured to irradiate pulsed laser light to generate ultrasonic waves into the molded object 15, a laser interferometer 62 configured to irradiate the molded object 15 with laser light and receive the reflected light to measure the vibration, i.e., displacement, of the surface of the molded object 15, and a flaw detection control unit 63. The flaw detection control unit 63 is configured with an electronic computing device such as a computer, and is capable of detecting the presence, location, and size of defects inside the fabricated object 15 based on vibrations of the surface of the fabricated object 15 detected by the laser interferometer 62.

[0025] (Challenges in conventional additive manufacturing processes) Within the area irradiated by the energy beam, the raw material powder 30 melts rapidly. As a result, defects may occur in the fabricated object 15, such as the formation of cavities inside the object 15. Therefore, in order to guarantee the quality of the molded object 15, it is necessary to perform non-destructive testing on the molded object 15 after the molding process is complete. However, non-destructive testing performed after the fabrication of object 15 is complete does not always detect all defects. Furthermore, non-destructive testing is time-consuming and costly.

[0026] Therefore, in some embodiments of the three-dimensional additive manufacturing apparatus 1, the presence or absence of defects in the fabricated object 15 and the powder bed 8 is detected for each layer 8a made of raw material powder 30, and any detected defects are repaired as follows.

[0027] (Regarding the additive manufacturing method according to the first embodiment using the three-dimensional additive manufacturing apparatus 1) Figure 2 is a flowchart showing the processing steps in the additive manufacturing method according to the first embodiment using the three-dimensional additive manufacturing apparatus 1 described above. The following explanation will follow the flowchart in Figure 2. In the additive manufacturing method according to the first embodiment, the manufacturing process is monitored as follows.

[0028] In step S11, the control unit 80, more specifically the calculation unit of the control unit 80, controls the powder laying unit 10 to lay the raw material powder 30. This forms a layer 8a of raw material powder 30 supplied from the storage unit 31.

[0029] Next, in step S13, the control unit 80 controls the second detection device 50 to detect the presence or absence of defects in the layer 8a made of raw material powder 30 based on the state of unevenness in the build surface area. As a result, the second detection device 50 projects a fringe pattern (striped pattern) onto the build surface area on the base plate 2 and detects the unevenness in the build surface area based on the image data acquired by the imaging unit 52. The second detection device 50 (unevenness detection unit 53) then detects the presence or absence of defects in the layer 8a based on the detection result of unevenness in the build surface area and outputs the result to the control unit 80.

[0030] In step S15, the control unit 80 determines whether or not there is a defect in layer 8a based on the information from the second detection device 50. If a defect is detected in layer 8a, the control unit 80 returns to step S11 and controls the powder laying unit 10 to lay the raw material powder 30. This causes the raw material powder 30 to be re-laid.

[0031] If it is determined that no defects exist in layer 8a, the control unit 80 controls the light beam irradiation device 20 to proceed to step S21 and irradiate with the light beam 71. As a result, the light beam irradiation device 20 irradiates with the light beam 71 based on the information received from the control unit 80 regarding the irradiation position of the light beam 71 for each layer 8a.

[0032] Furthermore, the control unit 80 controls the first detection device 40 in step S23 to detect the presence or absence of defects in the fabricated object 15, simultaneously with the irradiation of the light beam 71 in step S21. As a result, the first detection device 40 detects the presence or absence of defects in the fabricated object 15 based on the light emission intensity emitted from the fabricated object 15.

[0033] When an energy beam such as a light beam 71 is irradiated onto the layer 8a of the raw material powder 30, if the irradiation state of the energy beam changes for some reason, such as a decrease in the output of the energy beam, the intensity of light emitted from the fabricated object 15 will change. Furthermore, an undesirable change in the irradiation state of the energy beam may lead to insufficient melting of the raw material powder 30, potentially causing defects. According to the three-dimensional additive manufacturing apparatus 1 of this embodiment, it is possible to determine, for example, that a malfunction or other problem may be occurring in the three-dimensional additive manufacturing apparatus 1 based on changes in the light emission intensity emitted from the manufactured object 15.

[0034] Furthermore, if a change in light emission intensity occurs due to a malfunction of the three-dimensional additive manufacturing apparatus 1, for example, insufficient melting of the raw material powder 30 may cause a defect in the layer 8a currently being fabricated by the light beam 71. Therefore, if a change in light emission intensity occurs, for example due to a malfunction in the three-dimensional additive manufacturing apparatus 1, it is possible that there is a malfunction in the three-dimensional additive manufacturing apparatus 1, or that there is a malfunction in the layer 8a that is currently being fabricated by irradiating it with the light beam 71.

[0035] Furthermore, changes in light emission intensity caused by malfunctions in the three-dimensional additive manufacturing apparatus 1 are not due to changes in light emission intensity caused by malfunctions in the fabricated object 15 below the layer 8a currently being fabricated by the light beam 71, as described later. Therefore, even if changes in light emission intensity occur due to malfunctions in the three-dimensional additive manufacturing apparatus 1, it may not be necessary to repair the defects in step S29 or step S37 described later.

[0036] Furthermore, as a result of diligent research by the inventors, it was found that when an energy beam such as a light beam 71 is irradiated onto the layer 8a of the raw material powder 30, the intensity of light emitted from the fabricated object 15 changes if there are defects such as voids in the underlying layer, i.e., the fabricated layer below the layer 8a currently being irradiated with the energy beam. This changes occur compared to the case where there are no defects, resulting in differences in heat conduction and changes in the size of the molten pool, thus altering the intensity of light emitted from the fabricated object 15.

[0037] Figure 3 shows the light emission intensity and standard deviation of the light emission intensity emitted from a test specimen when layers are sequentially formed on a test specimen having a simulated defect. The leftmost figure in Figure 3 shows the light emission intensity and the standard deviation of the light emission intensity when a 0.5 mm square simulated defect is generated by not irradiating the 0.5 mm square area in the center of the figure with the light beam 71. The fabricated layer generated in this way is called the final layer of the simulated defect.

[0038] The second figure from the left in Figure 3 shows the light emission intensity and the standard deviation of the light emission intensity when a light beam 71 is irradiated onto raw material powder 30 laid directly on top of the final layer of the simulated defect. The fabricated layer thus produced is called the defect cover layer. If the final layer of the simulated defect described above is considered the first layer, then the defect cover layer corresponds to the second layer. Figure 3 shows that when creating the defect cover layer, the luminescence intensity and standard deviation of the luminescence intensity in the region directly above the defect differ from the luminescence intensity and standard deviation of the luminescence intensity in other regions, due to the influence of the simulated defect in the adjacent layer, i.e., the final layer of the simulated defect, which is the layer below the defect cover layer.

[0039] The rightmost figure in Figure 3 shows the light emission intensity and the standard deviation of the light emission intensity when a light beam 71 is irradiated onto the raw material powder 30 laid directly on top of the defect lid layer. The fabricated layer thus produced is called the post-lid fabricated layer. If the final layer of the simulated defect described above is considered the first layer, then the post-lid fabricated layer corresponds to the third layer. Figure 3 shows that when creating the post-lid layer, the luminescence intensity and standard deviation of the luminescence intensity in the region directly above the post-lid layer differ from the luminescence intensity and standard deviation of the luminescence intensity in other regions, due to the influence of the simulated defect in the final layer of the simulated defect, which is two layers below the adjacent layer (the defect lid layer).

[0040] According to the three-dimensional additive manufacturing apparatus 1 of this embodiment, when a light beam 71 is irradiated onto the layer 8a of the raw material powder 30, it is possible to detect the presence or absence of defects in the layers below the uppermost layer of the manufactured object 15, that is, in the layers below the layer 8a that is currently being irradiated with the light beam 71, based on the change in the light emission intensity of the light emitted from the manufactured object 15. In other words, according to the three-dimensional additive manufacturing apparatus 1 of this embodiment, it is possible to determine, for example, if there are defects or other problems in the manufactured object 15 below the layer 8a that is currently being manufactured by irradiating it with the light beam 71.

[0041] Therefore, according to the three-dimensional additive manufacturing apparatus 1 of this embodiment, it is possible to detect whether there is a possibility of a malfunction in the three-dimensional additive manufacturing apparatus 1, whether there is a possibility of a malfunction in the layer 8a currently being irradiated by the light beam 71, and whether there are defects such as voids in the fabricated layers below layer 8a, based on the emission intensity of light emitted from the fabricated object 15 by irradiation with the light beam 71.

[0042] In step S25, the control unit 80 determines whether or not the molded object 15 has a defect based on the information from the first detection device 40. If it is determined that the molded object 15 has a defect, the control unit 80 proceeds to step S27 and controls the flaw detection device 60 to inspect the molded object 15 and acquire the defect status. As a result, the flaw detection device 60 inspects the molded object 15 as described above and detects the defect status, that is, the presence or absence of defects inside the molded object 15, the location and size of the defects, and outputs the detection results to the control unit 80.

[0043] Next, in step S29, the control unit 80 controls the light beam irradiation device 20 to repair the defect based on the defect status acquired by the flaw detection device 60 in step S27. As a result, the light beam irradiation device 20 irradiates the fabricated object 15 with a light beam 71 based on the information about the location and size of the defect received from the control unit 80. This repairs the defect inside the fabricated object 15. Details regarding the repair of defects using the light beam irradiation device 20 will be explained later.

[0044] If it is determined in step S25 that there are no defects in the molded object 15, or if step S29 described above is performed, the process proceeds to step S31, where the control unit 80 controls the second detection device 50 to detect whether or not there are defects in the molded object 15 based on the state of unevenness in the molded surface area. As a result, the second detection device 50 projects a fringe pattern (striped pattern) onto the molded surface area on the base plate 2 and detects the unevenness in the molded surface area based on the image data acquired by the imaging unit 52. The second detection device 50 (unevenness detection unit 53) then detects whether or not there are defects on the upper surface of the molded object 15 based on the detection result of unevenness in the molded surface area and outputs the result to the control unit 80.

[0045] In step S33, the control unit 80 determines whether or not there is a defect on the upper surface of the molded object 15 based on the information from the second detection device 50. If a defect is detected on the upper surface of the molded object 15, the control unit 80 proceeds to step S35 and controls the flaw detection device 60 to inspect the molded object 15 and acquire the defect status. As a result, the flaw detection device 60 inspects the molded object 15 as described above, acquires the defect status, and outputs the detection result to the control unit 80.

[0046] Next, in step S37, the control unit 80 controls the light beam irradiation device 20 to repair the defect based on the defect status acquired by the flaw detection device 60 in step S35. As a result, the light beam irradiation device 20 irradiates the fabricated object 15 with a light beam 71 based on the information about the location and size of the defect received from the control unit 80. This repairs the defect in the fabricated object 15.

[0047] If it is determined in step S33 that there are no defects in the molded object 15, or if step S37 described above is performed, the process proceeds to step S41, where the control unit 80 determines whether or not the molding of the molded object 15 has been completed. If it is determined that the molding of the object 15 is not yet complete, the process proceeds to step S43, where the control unit 80 outputs a drive signal to the drive cylinder 2a to lower the base plate 2 by an amount equivalent to the thickness of one layer of layer 8a. As a result, the base plate 2 is lowered by an amount equivalent to the thickness of one layer of layer 8a. Once step S43 is executed, the process returns to step S11.

[0048] If it is determined in step S41 that the printing of the object 15 has been completed, the control unit 80 terminates the printing of the object 15.

[0049] The method for monitoring the fabrication process when fabricating an object 15 using the three-dimensional additive manufacturing apparatus 1 according to this embodiment includes step S11, which is the step of supplying raw material powder 30 to form a layer 8a of raw material powder 30. The method for monitoring the fabrication process according to this embodiment includes step S21, which is the step of fabricating a part of the object 15 by irradiating the layer 8a with an energy beam, which is a light beam 71, to melt and solidify the raw material powder 30 of the layer 8a. The method for monitoring the fabrication process according to this embodiment includes step S23, which is a first detection step, for detecting the presence or absence of defects in the object 15 while step S21 is being performed. The method for monitoring the fabrication process according to this embodiment includes step S31, which is a second detection step, for measuring the surface shape of the object 15 after step S21 has been performed and detecting the presence or absence of defects in the object 15 based on the surface shape of the object 15. In the method for monitoring the fabrication process according to this embodiment, the first detection step, step S23, and the second detection step, step S31, are performed each time step S21 is performed.

[0050] According to the manufacturing process monitoring method of this embodiment, the first detection step, step S23, is performed while step S21 is being executed, so the inspection time can be significantly reduced. Furthermore, in the second detection step, step S31, the presence or absence of defects in the manufactured object 15 is detected based on the surface shape of the manufactured object 15, so the inspection can be performed in a relatively short time. Therefore, according to the manufacturing process monitoring method of this embodiment, the inspection time of the manufactured object 15 can be suppressed. Furthermore, according to the manufacturing process monitoring method of this embodiment, by performing the first detection step S23 and the second detection step S31 each time step S21 is performed, non-destructive testing after the manufacturing of the manufactured object 15 is completed can be omitted, thereby reducing the inspection time and costs required for inspection of the manufactured object 15. According to the manufacturing process monitoring method of this embodiment, by performing the first detection step S23 and the second detection step S31 each time step S21 is performed, the accuracy of detecting defects in the manufactured object 15 can be improved compared to when the first detection step and the second detection step are performed individually, thereby improving the quality of the manufactured object 15.

[0051] According to the additive manufacturing method using the manufacturing process monitoring method of this embodiment, a high-quality manufactured object 15 can be obtained while suppressing the inspection time and inspection costs of the manufactured object 15.

[0052] In the manufacturing process monitoring method according to this embodiment, the presence or absence of defects in the manufactured object 15 is detected in step S23 based on the light emission intensity of the light emitted from the manufactured object 15 when the light beam 71 is irradiated in step S21 during the manufacturing process. This allows step S23 to be performed relatively easily with a relatively simple device configuration while step S21 is being carried out, thus suppressing the increase in equipment costs required to perform step S23.

[0053] In the method for monitoring the molding process according to this embodiment, in step S31, the surface shape of the molded object 15 is measured based on an image obtained by capturing a pattern projected onto the surface of the molded object 15. As a result, step S31 can be performed relatively easily with a relatively simple device configuration, which reduces the time required to perform step S31 and also suppresses the increase in equipment costs required to perform step S31.

[0054] In the manufacturing process monitoring method according to this embodiment, if a defect is detected in step S23 or step S31, the manufactured object 15 is inspected to obtain the defect status (steps S27 and S35). This allows for a more detailed understanding of the defect.

[0055] In the manufacturing process monitoring method according to this embodiment, the defect status is acquired by laser ultrasonic method in steps S27 and S35. This allows for a more detailed understanding of the defect's condition without destructive intervention.

[0056] In the manufacturing process monitoring method according to this embodiment, after performing step S11, which is the step of forming layer 8a, and before performing step S21, which is the step of manufacturing, step S13 is included, which is the step of measuring the surface shape of layer 8a and detecting the presence or absence of defects in layer 8a based on the surface shape of layer 8a. This makes it possible to determine the quality of the layer 8a formed by laying the raw material powder 30.

[0057] In the manufacturing process monitoring method according to this embodiment, if a defect is detected in layer 8a in step S13, the method includes a step (step S11) of supplying raw material powder 30 to reform layer 8a of raw material powder 30. This improves the integrity of the layer 8a formed by laying the raw material powder 30.

[0058] The three-dimensional additive manufacturing apparatus 1 according to this embodiment includes a powder bed forming unit 5 having a base plate 2 on which a layer 8a of supplied raw material powder 30 is formed. The three-dimensional additive manufacturing apparatus 1 according to this embodiment includes a light beam irradiation unit 20 capable of irradiating the layer 8a with a light beam 71, which is an energy beam. The three-dimensional additive manufacturing apparatus 1 according to this embodiment includes a first detection device 40 configured to detect the presence or absence of defects in the manufactured object 15 during irradiation with the light beam 71. The three-dimensional additive manufacturing apparatus 1 according to this embodiment includes a second detection device 50 configured to measure the surface shape of the manufactured object 15 after irradiation with the light beam 71 and to detect the presence or absence of defects in the manufactured object 15 based on the surface shape of the manufactured object 15. The powder bed forming unit 5 is configured to supply raw material powder 30 to form a layer 8a of raw material powder 30 after the first detection device 40 detects the presence or absence of defects in the manufactured object 15 and the second detection device 50 detects the presence or absence of defects in the manufactured object 15.

[0059] According to the three-dimensional additive manufacturing apparatus 1 of this embodiment, the presence or absence of defects in the manufactured object 15 is detected while the light beam 71 for manufacturing is irradiated, so the inspection time can be significantly reduced. In addition, the presence or absence of defects in the manufactured object 15 can be detected by the second detection device 50 based on the surface shape of the manufactured object 15, so inspection can be performed in a relatively short time. Therefore, according to the three-dimensional additive manufacturing apparatus 1 of this embodiment, the inspection time of the manufactured object 15 can be suppressed. Furthermore, according to the three-dimensional additive manufacturing apparatus 1 of this embodiment, the presence or absence of defects can be detected by the first detection device 40 and the second detection device 50 each time a layer 8a is manufactured. Therefore, non-destructive testing after the manufacturing of the manufactured object 15 is completed can be omitted, and the inspection time and cost of the manufactured object 15 can be reduced.

[0060] (Regarding the repair of defects using the light beam irradiation device 20) Figure 4 is a graph illustrating the relationship between the defect depth De and the output of the light beam 71 when repairing defects in the fabricated object 15. Figures 5A to 5G illustrate the scanning patterns of the light beam 71 when repairing defects in the fabricated object 15.

[0061] (Regarding the output of the light beam 71 during defect repair) In the three-dimensional additive manufacturing apparatus 1 according to this embodiment, when repairing defects in the manufactured object 15 in steps S29 and S37 described above, the defects are repaired by irradiating the light beam 71 with irradiation conditions set based on the defect state acquired in step S27 or step S35.

[0062] Specifically, the control unit 80 controls the light beam irradiation device 20 to repair the defect by irradiating it with the light beam 71 at the first output P1 if the defect depth De obtained in step S27 or step S35 is less than a specified depth De1. As a result, the light beam irradiation device 20 irradiates the light beam 71 with the first output P1 (see Figure 4). Here, the defect depth De is, for example, the distance from the surface of the molded object 15 to the bottom of a cavity or the like. Furthermore, the first output P1 is an output that can at least remelt the surface of the fabricated object 15. That is, the surface of the fabricated object 15 cannot be remelted unless the output of the irradiated light beam 71 exceeds a certain threshold. Therefore, if the defect depth De is less than the specified depth De1, the light beam 71 will be output at a first output P1 of the above threshold or higher, regardless of the defect depth De.

[0063] If the defect depth De obtained in step S27 or step S35 is greater than or equal to a specified depth De1, the control unit 80 controls the light beam irradiation device 20 to repair the defect by irradiating the light beam 71 with a second output P2 that has a greater output than the first output P1 and increases as the defect depth De increases. As a result, the light beam irradiation device 20 irradiates the light beam 71 with the second output P2 (see Figure 4).

[0064] In the three-dimensional additive manufacturing apparatus 1 according to this embodiment, defects in the manufactured object 15 are repaired in steps S29 and S37 described above, so defects can be repaired during the manufacturing process of the manufactured object 15. As a result, non-destructive testing after the manufacturing of the manufactured object 15 is completed can be omitted, and the inspection time and costs associated with the inspection of the manufactured object 15 can be reduced.

[0065] By setting the output of the light beam 71 when repairing defects in the fabricated object 15 in steps S29 and S37 described above, defects can be repaired with an output of the light beam 71 corresponding to the depth De of the defect, thereby improving the reliability of defect repair. Furthermore, when repairing defects in the fabricated object 15 in steps S29 and S37 described above, even if the defect depth De is less than the specified depth De1, irradiating it with the light beam 71 of the first output P1 can suppress the occurrence of problems that would prevent the surface of the fabricated object 15 from being remelted during defect repair.

[0066] (Regarding the scanning of the light beam 71 during defect repair) In the three-dimensional additive manufacturing apparatus 1 according to this embodiment, when repairing defects in the manufactured object 15 in steps S29 and S37 described above, it is determined whether or not to scan the light beam 71 based on the maximum dimension dmax of the defect when the defect is viewed from above the manufactured object 15. In the three-dimensional additive manufacturing apparatus 1 according to this embodiment, if the maximum dimension dmax of a defect is less than twice the beam width db of the light beam 71 (dmax < 2 × db), the defect is repaired by irradiating it with the light beam 71 without scanning. In the three-dimensional additive manufacturing apparatus 1 according to this embodiment, if the maximum dimension dmax of a defect is twice or more the beam width db of the light beam 71 (dmax ≥ 2 × db), the defect is repaired by irradiating it while scanning with the light beam 71. This allows the light beam 71 to be irradiated under appropriate irradiation conditions depending on the size of the defect.

[0067] When repairing defects by scanning with the light beam 71, the scanning pattern may be as shown in Figures 5A to 5G. In Figures 5A to 5G, the scanning pattern of the light beam 71 is represented by arrows. For example, the scanning pattern shown in Figure 5A is an example of scanning the light beam 71 along the circumferential direction. For example, the scanning pattern shown in Figure 5B is an example of scanning the light beam 71 along the sides of a rectangle. For example, the scanning pattern shown in Figure 5C is an example of scanning in which the light beam 71 is moved linearly back and forth between one side and the other within a certain region, so as to fill that region with light.

[0068] For example, the scanning pattern shown in Figure 5D is an example of scanning the light beam 71 along the circumferential direction to draw multiple concentric circles. For example, the scanning pattern shown in Figure 5E is an example of scanning the optical beam 71 along the sides of a rectangle to draw multiple concentric rectangles. For example, the scanning pattern shown in Figure 5F is an example of a case where the light beam 71 is scanned along the circumferential direction and the light beam 71 is scanned by moving it linearly back and forth between one side and the other within a circular area to fill that area. For example, the scanning pattern shown in Figure 5G is an example of scanning the light beam 71 along the edges of a rectangle and scanning the light beam 71 back and forth in a straight line between one side and the other within the rectangular area so as to fill the area.

[0069] Furthermore, the scanning pattern when repairing defects by irradiating with the light beam 71 while scanning is not limited to the scanning pattern described above.

[0070] (Regarding the additive manufacturing method according to the second embodiment) The additive manufacturing method according to the second embodiment will be described below. Figure 6 is a flowchart showing the processing steps in the additive manufacturing method according to the second embodiment using the three-dimensional additive manufacturing apparatus 1 described above. In the following description, the same reference numerals are used for the same processes as in the additive manufacturing method according to the first embodiment, and detailed explanations may be omitted.

[0071] In the additive manufacturing method according to the second embodiment, even if it is determined that there is a defect in the manufactured object 15 based on information from the first detection device 40, or if it is determined that there is a defect on the upper surface of the manufactured object 15 based on information from the second detection device 50, if the defect in the manufactured object 15 detected by the first detection device 40 or the second detection device 50 is determined to be minute, the process proceeds to the next step without performing any processing to repair the defect in the manufactured object 15.

[0072] The process from step S11 to step S25 in Figure 6 is the same as the process from step S11 to step S25 in Figure 2. If step S25 is deemed negative, the control unit 80 proceeds to step S31. If step S25 is determined to be positive, the process proceeds to step S61, where the control unit 80 determines whether the defect in the fabricated object 15 detected in step S23 is minute or not. In step S61, if the control unit 80 determines that the defect in the fabricated object 15 detected in step S23 is minute, it proceeds to step S31 without performing steps S27 and S29. In step S61, if the control unit 80 determines that the defect in the fabricated object 15 detected in step S23 is not minute, the control unit 80 proceeds to step S27.

[0073] The process from step S27 to step S33 in Figure 6 is the same as the process from step S27 to step S33 in Figure 2. If step S33 is deemed negative, the control unit 80 proceeds to step S41. If step S33 is determined to be positive, the process proceeds to step S63, where the control unit 80 determines whether the defect in the fabricated object 15 detected in step S31 is minute or not. In step S63, if the control unit 80 determines that the defect in the fabricated object 15 detected in step S31 is minute, it proceeds to step S41 without performing steps S35 and S37. In step S63, if the control unit 80 determines that the defect in the fabricated object 15 detected in step S31 is not minute, the control unit 80 proceeds to step S35.

[0074] The processes from step S35 onwards in Figure 6, and from step S41 onwards in Figure 6, are the same as the processes from step S35 onwards in Figure 2, and from step S41 onwards in Figure 2. Furthermore, if in step S61 it is determined that the defect in the fabricated object 15 detected in step S23 is minute, or if in step S63 it is determined that the defect on the upper surface of the fabricated object 15 detected in step S31 is minute, the three-dimensional additive manufacturing apparatus 1 may be configured to notify the operator of the three-dimensional additive manufacturing apparatus 1 that the defect in the fabricated object 15 was minute, or to inform the operator of the defect in the fabricated object 15 that the defect in the fabricated object 15 was minute.

[0075] (Regarding the additive manufacturing method according to the third embodiment) The additive manufacturing method according to the third embodiment will be described below. Figure 7 is a flowchart showing the processing steps in the additive manufacturing method according to the third embodiment using the three-dimensional additive manufacturing apparatus 1 described above. In the following description, the same reference numerals are used for the same processes as in the additive manufacturing method according to the first embodiment and the additive manufacturing method according to the second embodiment, and detailed explanations may be omitted. The process from step S11 to step S21 in Figure 7 is the same as the process from step S11 to step S21 in Figure 2. When step S21 in Figure 7 is performed, the process proceeds to step S51, and when step S51 is performed, the process proceeds to step S53. The following describes the processing contents of steps S51 and S53 in the additive manufacturing method according to the third embodiment.

[0076] In some embodiments of the additive manufacturing method, the emission intensity of light detected by the light detection unit 41 is continuously acquired, more specifically, at minute scanning distance intervals, during the scanning of the light beam 71. The inventors extracted the maximum value Smax, the average value Save, and the minimum value Smin of multiple luminescence intensity measurements obtained during the fabrication of one layer for each layer, and investigated the trends.

[0077] After diligent investigation by the inventors, it was found that if there are no defects (cavities) inside the molded object 15, or if there are only minute defects, the above-mentioned maximum value Smax, average value Save, and minimum value Smin remain relatively stable in all molded layers.

[0078] After diligent investigation by the inventors, it was found that when a defect that is not insignificant is present inside the molded object 15, the average value Save only shows slight fluctuations when printing the molded layer containing the defect, making it difficult to determine whether or not there is a defect inside the molded object 15 based on changes in the average value Save. After diligent investigation by the inventors, it was found that when there are defects that are not necessarily minute inside the fabricated object 15, the minimum value Smin remains relatively stable in all fabricated layers.

[0079] However, after careful consideration by the inventors, it was found that when there is a defect that is not insignificant inside the molded object 15, the maximum value Smax detected during the molding of the layer in which the defect (cavity) was present is relatively larger than the maximum value Smax when there is no defect (cavity) inside the molded object 15, or when the defect is insignificant.

[0080] Therefore, in the additive manufacturing method according to the third embodiment, when determining whether or not there is a defect in the manufactured object 15 based on information from the first detection device 40, attention is paid to the maximum value Smax of multiple luminescence intensity measurements obtained during the manufacturing of one layer. In other words, in the additive manufacturing method according to the third embodiment, the representative value Rv of the luminescence intensity of a particular layer is set as the average of a predetermined number of luminescence intensity measurements obtained during the manufacturing of one layer, ordered from largest to smallest. When the predetermined number is 1, the representative value Rv is the maximum value of the multiple luminescence intensity measurements obtained during the manufacturing of one layer. Alternatively, from among the multiple luminescence intensity measurements obtained during the printing of one layer of the build plate, a predetermined proportion of the measurements obtained during the printing of one layer of the build plate are extracted in descending order of value, and their average value is taken as the representative value Rv of the luminescence intensity of that build plate. Furthermore, in the additive manufacturing method according to the third embodiment, the presence or absence of defects in the manufactured object 15 is detected based on this representative value Rv and a predetermined reference value Ref. In other words, in step S51, the control unit 80 obtains the representative value Rv from the detection result of the light emission intensity in the first detection device 40. Then, as will be described later, the control unit 80 determines whether or not there are defects in the molded object 15 based on the representative value Rv and a predetermined reference value Ref. In step S51, the control unit 80 may also determine whether or not there are defects in the molded object 15 that was fabricated in step S23 of Figure 2 according to the first embodiment described above.

[0081] Here, the above reference value Ref is a predetermined value as the maximum value Smax that can be measured when there are no defects (cavities) inside the molded object 15, or if there are defects, they are minute defects. This value may be, for example, the average value of the maximum value Smax obtained by molding a large number of molded objects 15 under the same irradiation conditions as the irradiation conditions of the light beam 71 when molding the molded object 15, or it may be, for example, the average value of the maximum value Smax obtained when the molded object 15 was experimentally molded under the same irradiation conditions as the irradiation conditions of the light beam 71 when molding the molded object 15.

[0082] As described above, if there is a defect that is not minute inside the molded object 15, the maximum value Smax detected during the molding of the layer in which the defect (cavity) was present will be a relatively large value compared to the maximum value Smax when there is no defect (cavity) inside the molded object 15, or when the defect is minute. Therefore, the representative value Rv during the molding of the layer in which the defect (cavity) was present will be a relatively large value compared to the predetermined reference value Ref. In other words, there is a correlation between the comparison result between the representative value Rv and the reference value Ref and the presence or absence of defects in the molded object 15.

[0083] In the method for monitoring the manufacturing process according to the additive manufacturing method according to the third embodiment, in the first detection step (step S51), at least one measurement value obtained from among multiple measurements of luminescence intensity obtained by measuring the luminescence intensity multiple times during the execution of one manufacturing step (step S21) is set as the representative value Rv of the luminescence intensity during the execution of one manufacturing step, in order from the measurement value with the largest luminescence intensity, and the presence or absence of defects in the manufactured object 15 may be detected based on the representative value Rv and a predetermined reference value Ref. According to the additive manufacturing method of the third embodiment, the presence or absence of defects in the manufactured object 15 can be detected based on the representative value Rv and the reference value Ref, thereby improving the accuracy of detecting the presence or absence of defects in the manufactured object 15.

[0084] More specifically, in the additive manufacturing method according to the third embodiment, the presence or absence of defects in the manufactured object 15 is detected by whether or not the representative value Rv is equal to or greater than a threshold Th determined based on the reference value Ref. Here, the threshold Th is a value that is larger by a specified percentage relative to the reference value Ref. For example, the threshold Th may be 1.5 times the reference value Ref.

[0085] In other words, in step S51, the control unit 80 compares the representative value Rv with the threshold Th, and determines that there are no defects in the molded object 15 if the representative value Rv is less than the threshold Th. In step S51, the control unit 80 compares the representative value Rv with the threshold Th, and determines that there is a defect in the molded object 15 if the representative value Rv is greater than or equal to the threshold Th.

[0086] If step S51 is performed, the process proceeds to step S53. If it is determined in step S51 that there are no defects in the molded object 15, the process proceeds to step S31. If it is determined that there are defects in the molded object 15, the process proceeds to step S61.

[0087] In the method for monitoring the manufacturing process related to the additive manufacturing method according to the third embodiment, in the first detection step (step S51), if the representative value Rv is less than the threshold Th determined based on the reference value Ref, it is determined that there are no defects in the manufactured object 15, and if the representative value Rv is equal to or greater than the threshold Th, it is determined that there are defects in the manufactured object 15. According to the additive manufacturing method of the third embodiment, the presence or absence of defects in the manufactured object 15 can be detected by comparing the representative value Rv with the threshold value Th, thereby improving the accuracy of detecting the presence or absence of defects in the manufactured object 15.

[0088] As a result of diligent research by the inventors, it was found that when the process of creating a single layer is performed multiple times, if the frequency of occurrence of a representative value Rv that is above the threshold Th is low, the likelihood of defects in the created object 15 is low, and if the frequency of occurrence of a representative value Rv that is above the threshold Th is high, the likelihood of defects in the created object 15 is high. Therefore, in the additive manufacturing method according to the third embodiment, if the frequency of occurrence Fr of a representative value Rv that is above a threshold when the single-layer manufacturing is performed multiple times is less than a specified frequency Fr1, it may be determined that there are no defects in the manufactured object 15. If the frequency of occurrence Fr of a representative value Rv that is above a threshold Th is greater than or equal to a specified frequency Fr1, it may be determined that there are defects in the manufactured object 15.

[0089] In other words, in step S51, the control unit 80 may compare the occurrence frequency Fr with a specified occurrence frequency Fr1, and if the occurrence frequency Fr is less than the specified occurrence frequency Fr1, it may determine that there are no defects in the molded object 15. In step S51, the control unit 80 may compare the occurrence frequency Fr with a specified occurrence frequency Fr1 and determine that there is a defect in the molded object 15 if the occurrence frequency Fr is equal to or greater than the specified occurrence frequency Fr1.

[0090] In the method for monitoring the manufacturing process related to the additive manufacturing method according to the third embodiment, in the first detection step (step S51), if the frequency of occurrence Fr of the representative value Rv that becomes greater than or equal to the threshold Th when the manufacturing step (step S21) is performed multiple times is less than a specified frequency Fr1, it may be determined that there are no defects in the manufactured object 15. If the frequency of occurrence Fr of the representative value that becomes greater than or equal to the threshold Th is greater than or equal to a specified frequency Fr1, it may be determined that there are defects in the manufactured object 15. This allows for the detection of defects in the fabricated object 15 based on the frequency Fr of occurrence of representative values ​​Rv that are above the threshold Th, thereby improving the accuracy of defect detection in the fabricated object 15.

[0091] The processes from step S61 onwards in Figure 7, and the processes from step S31 onwards in Figure 7, are the same as the processes from step S61 onwards in Figure 6, and the processes from step S31 onwards in Figure 6.

[0092] (Regarding the additive manufacturing method according to the fourth embodiment) The additive manufacturing method according to the fourth embodiment will be described below. Figure 8 is a flowchart showing the processing steps in the additive manufacturing method according to the fourth embodiment using the three-dimensional additive manufacturing apparatus 1 described above. In the following description, the same reference numerals are used for processes that are the same as those described in the additive manufacturing methods of each embodiment described above, and detailed explanations may be omitted. The process from step S11 to step S25 in Figure 8 is the same as the process from step S11 to step S25 in Figure 2. If step S25 is deemed negative, the control unit 80 proceeds to step S31. If step S25 in Figure 8 is determined to be positive, the process proceeds to step S61, where the control unit 80 determines whether the defect in the fabricated object 15 detected in step S23 is minute or not. In step S61, if the control unit 80 determines that the defect in the fabricated object 15 detected in step S23 is minute, it proceeds to step S31 without performing steps S26, S27, and S29. If, in step S61, the control unit 80 determines that the defect in the fabricated object 15 detected in step S23 is not minute, the control unit 80 proceeds to step S26. The following describes the processing content of step S26 in the additive manufacturing method according to the fourth embodiment.

[0093] For example, if a laser beam is shone obliquely onto the surface of the object 15, that is, if the laser beam is shone from an angle inclined with respect to the normal direction of the surface of the object 15, the scattered light from the surface of the object 15 will be affected by the surface roughness if the surface roughness of the object 15 is relatively large. Therefore, when acquiring the condition of a defect using the laser ultrasonic method, as in the flaw detection device 60 described above, it becomes difficult to accurately acquire the condition of the defect. Furthermore, the surface roughness of the molded object 15 is generally relatively high. Therefore, the accuracy of the flaw detection device 60 in detecting the presence, location, and size of defects inside the molded object 15 may decrease.

[0094] Therefore, in the additive manufacturing method according to the fourth embodiment, after step S25 is determined to be positive and step S61 is determined to be negative, and before the defect status is obtained by inspecting the manufactured object 15 with the flaw detection device 60 in step S27, in step S26 the surface of the manufactured object 15 is processed by irradiating it with a beam to make the surface roughness of the manufactured object 15 less than before the beam irradiation. In other words, the additive manufacturing method according to the fourth embodiment includes step S26 in which, when a defect in the manufactured object 15 is detected based on information from the first detection device 40, the surface of the manufactured object is processed by irradiating it with a beam.

[0095] In the additive manufacturing method according to the fourth embodiment, the beam irradiated onto the manufactured object 15 in step S26 is the light beam 71 irradiated by the light beam irradiation unit 21 of the light beam irradiation device 20. The irradiation conditions of the light beam 71, such as the output of the light beam 71 irradiated onto the manufactured object 15 in step S26, are set to irradiation conditions suitable for processing the surface of the manufactured object 15 and making the surface roughness of the manufactured object 15 relatively small.

[0096] If step S61 is deemed negative (i.e., if it is determined that the defect in the fabricated object 15 is not minute), the control unit 80 proceeds to step S26 and controls the light beam irradiation device 20 to irradiate the fabricated object 15 with the light beam 71 under irradiation conditions suitable for processing the surface of the fabricated object 15 and making the surface roughness of the fabricated object 15 relatively small. As a result, the surface of the fabricated object 15 is irradiated with the light beam 71, and the surface roughness of the fabricated object 15 becomes relatively small.

[0097] Once step S26 is completed, the process proceeds to step S27. The process from step S27 to step S33 in Figure 8 is the same as the process from step S27 to step S33 in Figure 6.

[0098] In step S35 of Figure 8, the molded object 15 is inspected by the flaw detection device 60, similar to step S27, to obtain information about any defects. Therefore, in the additive manufacturing method according to the fourth embodiment, after step S33 is determined to be positive and step S63 is determined to be negative, and before the defect status is obtained by inspecting the manufactured object 15 with the flaw detection device 60 in step S35, in step S34 the surface of the manufactured object 15 is processed by irradiating it with a beam to make the surface roughness of the manufactured object 15 less than before the beam irradiation. In other words, the additive manufacturing method according to the fourth embodiment includes step S34 in which, when a defect in the manufactured object 15 (a defect on the upper surface of the manufactured object 15) is detected based on information from the second detection device 50, the surface of the manufactured object 15 is processed by irradiating it with a beam.

[0099] In the additive manufacturing method according to the fourth embodiment, the beam irradiated onto the manufactured object 15 in step S34 is the light beam 71 irradiated by the light beam irradiation unit 21 of the light beam irradiation device 20. The irradiation conditions of the light beam 71, such as the output of the light beam 71 irradiated onto the manufactured object 15 in step S34, are set to irradiation conditions suitable for processing the surface of the manufactured object 15 and making the surface roughness of the manufactured object 15 relatively small.

[0100] If step S33 is deemed negative, the control unit 80 proceeds to step S41. If step S33 is determined to be positive, the process proceeds to step S63, where the control unit 80 determines whether the defect on the upper surface of the fabricated object 15 detected in step S31 is minute or not. In step S63, if the control unit 80 determines that the defect on the upper surface of the fabricated object 15 detected in step S31 is minute, it proceeds to step S41 without performing steps S34, S35, and S37. In step S63, if the control unit 80 determines that the defect on the upper surface of the fabricated object 15 detected in step S31 is not minute, the control unit 80 proceeds to step S34. In step S34, the control unit 80 controls the light beam irradiation device 20 to irradiate the fabricated object 15 with a light beam 71 under irradiation conditions suitable for processing the surface of the fabricated object 15 and making the surface roughness of the fabricated object 15 relatively small. As a result, the surface of the fabricated object 15 is irradiated with the light beam 71, and the surface roughness of the fabricated object 15 becomes relatively small.

[0101] In the method for monitoring the manufacturing process related to the additive manufacturing method according to the fourth embodiment, when a defect is detected in the first detection step (step S23, step S51) or the second detection step (step S31), the method may include a step of processing the surface of the manufactured object 15 by irradiating it with a beam (step S26, step S34), and a step of inspecting the manufactured object 15 whose surface has been processed in the step of processing the surface of the manufactured object 15 (step S26, step S34) to obtain the defect status (step S27, step S35). According to the additive manufacturing method of the fourth embodiment, even when performing inspections that are susceptible to the surface roughness of the manufactured object 15, such as those performed by a flaw detection device 60 using laser ultrasonic testing, it becomes easier to ensure the accuracy of the inspection results. Furthermore, according to the additive manufacturing method of the fourth embodiment, the surface of the manufactured object 15 is processed by the light beam 71 irradiated by the light beam irradiation unit 21 of the light beam irradiation device 20, so no additional equipment is required and the surface of the manufactured object 15 can be processed relatively easily.

[0102] Once step S34 is completed, the process proceeds to step S35. The processing from step S35 onwards in Figure 8, and the processing from step S41 onwards in Figure 8, are the same as the processing from step S35 onwards in Figure 6, and the processing from step S41 onwards in Figure 6.

[0103] If step S26 is performed prior to step S34, the defect will have been repaired in step S29. In this case, the beam irradiation in step S34 may be performed only on the repaired area and its surroundings in step S29.

[0104] (Regarding the additive manufacturing method according to the fifth embodiment) The additive manufacturing method according to the fifth embodiment will be described below. The additive manufacturing method according to the fifth embodiment differs from the additive manufacturing method according to the fourth embodiment described above in that the source of the beam irradiated onto the manufactured object 15 in steps S26 and S34 is different, but otherwise it is the same as the fourth embodiment described above.

[0105] In the additive manufacturing method according to the fourth embodiment described above, the beam irradiated onto the manufactured object 15 in steps S26 and S34 was the light beam 71 irradiated by the light beam irradiation unit 21 of the light beam irradiation device 20. In the additive manufacturing method according to the fifth embodiment, the beam irradiated onto the manufactured object 15 in steps S26 and S34 is laser light irradiated by the laser irradiation device 61 of the flaw detection device 60. Furthermore, the laser irradiation conditions for the laser beam emitted by the laser irradiation device 61 in steps S26 and S34, including the output of the laser beam, are set to irradiation conditions suitable for processing the surface of the molded object 15 and making the surface roughness of the molded object 15 relatively small.

[0106] According to the additive manufacturing method of the fifth embodiment, the surface of the manufactured object 15 is processed by laser light emitted by the laser irradiation device 61 provided in the flaw detection device 60. Therefore, no additional equipment is required, and the surface of the manufactured object 15 can be processed relatively easily.

[0107] (Regarding the additive manufacturing method according to the sixth embodiment) The additive manufacturing method according to the sixth embodiment will be described below. The additive manufacturing method according to the sixth embodiment differs from the additive manufacturing methods according to the fourth and fifth embodiments described above in that the source of the beam irradiated onto the manufactured object 15 in steps S26 and S34 is different, but otherwise it is the same as the fourth and fifth embodiments described above.

[0108] Figure 9 is a schematic diagram showing the overall configuration of a three-dimensional additive manufacturing apparatus 1A, which is an additive manufacturing apparatus to which the additive manufacturing method according to the sixth embodiment can be applied. The three-dimensional additive manufacturing apparatus 1A shown in Figure 9 has the same configuration as the three-dimensional additive manufacturing apparatus 1 shown in Figure 1, except that a surface treatment irradiation device 90 has been added. The surface processing irradiation device 90 is a device for irradiating the surface of the molded object 15 with laser light 95, and includes a laser light irradiation unit 91 capable of irradiating laser light 95, and a laser light control unit 92 that controls the laser light irradiation unit 91. The laser beam control unit 92 is configured as an electronic computing device such as a computer, and is configured to control the irradiation position of the laser beam 95 emitted by the laser beam irradiation unit 91 based on information received from the control unit 80. Furthermore, the irradiation conditions for the laser beam 95 emitted by the laser beam irradiation unit 91 in steps S26 and S34, including the output of the laser beam, are set to irradiation conditions suitable for processing the surface of the molded object 15 and making the surface roughness of the molded object 15 relatively small.

[0109] According to the additive manufacturing method of the sixth embodiment, setting work is not required when changing the irradiation conditions in the light beam irradiation unit 21 of the light beam irradiation device 20 or the laser irradiation device 61 of the flaw detection device 60.

[0110] This disclosure is not limited to the embodiments described above, but also includes modified forms of the embodiments described above, as well as forms that combine these forms as appropriate.

[0111] The contents described in each of the above embodiments can be understood, for example, as follows: (1) A method for monitoring a molding process according to at least one embodiment of the present disclosure comprises: a step (step S21) of forming a part of a molded object 15 by irradiating a layer 8a of raw material powder 30 with an energy beam (light beam 71) to melt and solidify the raw material powder 30 in the layer 8a; a first detection step (steps S23, S51) of detecting whether or not there are defects in the molded object 15 during the molding step (step S21); and a second detection step (step S31) of measuring the surface shape of the molded object 15 after the molding step (step S21) has been performed and detecting whether or not there are defects in the molded object 15 based on the surface shape of the molded object 15. The first detection step (steps S23, S51) and the second detection step (step S31) are performed each time the molding step (step S21) is performed.

[0112] According to the method described in (1) above, the first detection step (steps S23 and S51) is performed while the molding step (step S21) is being carried out, so the inspection time can be significantly reduced. In addition, in the second detection step (step S31), the presence or absence of defects in the molded object 15 is detected based on the surface shape of the molded object 15, so the inspection can be performed in a relatively short time. Therefore, according to the method described in (1) above, the inspection time of the molded object 15 can be reduced. Furthermore, according to the method described in (1) above, by performing the first detection step (step S23, step S51) and the second detection step (step S31) each time the molding step (step S21) is carried out, non-destructive testing after the molding of the molded object 15 is completed can be omitted, thereby reducing the inspection time and costs required for the inspection of the molded object 15.

[0113] (2) In some embodiments, in the method of (1) described above, the first detection step (step S23, step S51) may detect whether or not there are defects in the fabricated object 15 based on the light emission intensity of the light emitted from the fabricated object 15 when an energy beam (light beam 71) is irradiated in the fabrication step (step S21).

[0114] According to the method described in (2) above, the first detection step (steps S23 and S51) can be performed relatively easily with a relatively simple device configuration while the molding step (step S21) is being carried out, thus suppressing the increase in device costs required to perform the first detection step (steps S23 and S51).

[0115] (3) In some embodiments, in the method of (2) described above, the first detection step (step S23) may detect the presence or absence of defects in the molding layer below the uppermost molding layer of the molded object 15 based on the light emission intensity.

[0116] According to the method described in (3) above, when an energy beam (light beam 71) is irradiated onto the layer 8a of the raw material powder 30, the presence or absence of defects in the layers below the uppermost layer of the fabricated object 15 can be detected based on the light emission intensity emitted from the fabricated object 15.

[0117] (4) In some embodiments, in the method of (2) or (3) above, the first detection step (step S23) may detect the presence or absence of defects in the uppermost layer of the molded object 15 based on the light emission intensity.

[0118] According to the method described in (4) above, for example, it is possible to detect the occurrence of defects in the fabricated object 15 caused by undesirable changes in the irradiation state of the energy beam (light beam 71).

[0119] (5) In some embodiments, in the method of (2) described above, in the first detection step (step S51), at least one measurement value obtained by measuring the luminescence intensity multiple times during the execution of one molding step (step S21) is selected from among multiple luminescence intensity measurements in descending order of luminescence intensity to be a representative value Rv of the luminescence intensity during one molding step, and the presence or absence of defects in the molded object 15 is detected based on the representative value Rv and a predetermined reference value Ref.

[0120] As a result of diligent investigation by the inventors, it was found that there is a correlation between the comparison result between the above representative value Rv and the above reference value Ref and the presence or absence of defects in the molded object 15. According to the method described in (5) above, the presence or absence of defects in the molded object 15 can be detected based on the representative value Rv and the reference value Ref, thereby improving the accuracy of detecting the presence or absence of defects in the molded object 15.

[0121] (6) In some embodiments, in the method of (5) described above, in the first detection step (step S51), it is preferable to determine that there are no defects in the molded object 15 if the representative value Rv is less than the threshold Th determined based on the reference value Ref, and to determine that there are defects in the molded object 15 if the representative value Rv is equal to or greater than the threshold Th.

[0122] According to the method described in (6) above, the presence or absence of defects in the molded object 15 can be detected by comparing the representative value Rv with the threshold value Th, thereby improving the accuracy of detecting the presence or absence of defects in the molded object 15.

[0123] (7) In some embodiments, in the method of (6) described above, in the first detection step (step S51), if the frequency of occurrence Fr of the representative value Rv that becomes greater than or equal to the threshold Th when the molding step (step S21) is performed multiple times is less than a specified frequency of occurrence Fr1, it may be determined that there are no defects in the molded object 15, and if the frequency of occurrence Fr of the representative value that becomes greater than or equal to the threshold Th is greater than or equal to a specified frequency of occurrence Fr1, it may be determined that there are defects in the molded object 15.

[0124] According to the method described in (7) above, the presence or absence of defects in the fabricated object 15 can be detected by the frequency Fr of occurrence of representative values ​​Rv that are above the threshold Th, thereby improving the accuracy of detecting the presence or absence of defects in the fabricated object 15.

[0125] (8) In some embodiments, in any of the methods (1) to (7) above, the second detection step (step S31) may be used to measure the surface shape of the molded object 15 based on an image obtained by imaging a pattern projected onto the surface of the molded object 15.

[0126] According to the method described in (8) above, the second detection step (step S31) can be performed relatively easily with a relatively simple device configuration, so the time required to perform the second detection step (step S31) is relatively short, and the cost increase of the device required to perform the second detection step (step S31) can be suppressed.

[0127] (9) In some embodiments, if a defect is detected in the first detection step (step S23, step S51) or the second detection step (step S31) of any of the methods (1) to (8) above, the method may include a step of inspecting the molded object 15 and obtaining the defect status (step S27, step S35).

[0128] According to the method described in (9) above, a more detailed understanding of the defect can be obtained.

[0129] (10) In some embodiments, if a defect is detected in any of the methods (1) to (8) above in the first detection step (step S23, step S51) or the second detection step (step S31), the method may include a step of processing the surface of the molded object 15 by irradiating it with a beam (step S26, step S34), and a step of inspecting the molded object 15 whose surface has been processed in the step of processing the surface of the molded object 15 (step S26, step S34) to obtain the state of the defect (step S27, step S35).

[0130] According to the method described in (10) above, by processing the surface roughness 15 of the fabricated object 15 by irradiating it with a beam, it becomes easier to ensure the accuracy of inspection results, even when performing inspections that are susceptible to the surface roughness of the fabricated object 15.

[0131] (11) In some embodiments, in the method of (9) or (10) above, the defect state may be acquired by laser ultrasonic method in the acquisition step (step S27, step S35).

[0132] According to the method described in (11) above, a more detailed understanding of the defect can be obtained non-destructively.

[0133] (12) In some embodiments, the method of (11) above may include a step (step S29, step S37) of repairing the defect by irradiating it with an energy beam (light beam 71) under irradiation conditions set based on the defect state acquired in the acquisition step (step S27, step S35).

[0134] According to the method described in (12) above, defects can be repaired during the molding process of the molded object 15, so non-destructive testing after the molding of the molded object 15 is completed can be omitted, and the inspection time and costs required for inspection of the molded object 15 can be reduced.

[0135] (13) In some embodiments, in the method of (12) above, in the repair step (step S29, step S37), if the depth De of the defect acquired in the acquisition step (step S27, step S35) is less than the specified depth De1, the defect may be repaired by irradiating it with an energy beam (light beam 71) at the first output P1. In the repair step (step S29, step S37), if the depth De of the defect acquired in the acquisition step (step S27, step S35) is greater than or equal to the specified depth De1, the defect may be repaired by irradiating it with an energy beam (light beam 71) at a second output P2 which has a greater output than the first output P1 and increases as the depth De of the defect increases.

[0136] According to the method described in (13) above, defects can be repaired with an energy beam (light beam 71) output corresponding to the depth of the defect, thereby improving the reliability of defect repair. Furthermore, even if the defect depth De is relatively shallow, the output of the energy beam (light beam 71) used for irradiation must be above a certain level to remelt the surface of the fabricated object 15. According to the method described in (13) above, even if the defect depth De is less than the specified depth De1, irradiating it with the first output P1 energy beam (light beam 71) can suppress the occurrence of problems that would prevent the surface of the fabricated object 15 from being remelted during defect repair.

[0137] (14) In some embodiments, in the repair step (step S29, step S37) of the method described in (12) or (13) above, if the maximum dimension dmax of the defect when viewed from above the fabricated object 15 is less than twice the beam width db of the energy beam (light beam 71), the defect may be repaired by irradiating it with the energy beam (light beam 71) without scanning. In the repair step (step S29, step S37), if the maximum dimension dmax of the defect when viewed from above the fabricated object 15 is twice or more the beam width db of the energy beam (light beam 71), the defect may be repaired by irradiating it with the energy beam (light beam 71) while scanning.

[0138] According to the method described in (14) above, an energy beam (light beam 71) can be irradiated with appropriate irradiation conditions according to the size of the defect. Therefore, when repairing relatively small defects, excessive heating of the fabricated object 15 can be suppressed, and when repairing relatively large defects, the heating necessary for defect repair can be performed. This improves the quality of the fabricated object 15.

[0139] (15) In some embodiments, after performing the step of forming the layer 8a (step S11) and before performing the molding step (step S21), the method of (1) to (14) above may include a step of measuring the surface shape of the layer 8a and detecting whether or not there are defects in the layer 8a based on the surface shape of the layer 8a (step S13).

[0140] According to the method described in (15) above, the quality of the layer 8a formed by laying the raw material powder 30 can be determined.

[0141] (16) In some embodiments, the method of (15) above may include a step of supplying raw material powder 30 to reform the layer 8a of raw material powder 30 if a defect is detected in the detection step (step S13) (step S11).

[0142] According to the method described in (16) above, the integrity of the layer 8a formed by laying the raw material powder 30 can be improved.

[0143] (17) An additive manufacturing apparatus (three-dimensional additive manufacturing apparatus 1) according to at least one embodiment of the present disclosure includes a powder bed forming unit 5 having a base plate 2 on which a layer 8a of supplied raw material powder 30 is formed, an energy beam irradiation unit (light beam irradiation device 20) capable of irradiating the layer 8a with an energy beam (light beam 71), a first detection device 40 configured to detect whether or not there are defects in the manufactured object 15 during irradiation with the energy beam (light beam 71), and a second detection device 50 configured to measure the surface shape of the manufactured object 15 after irradiation with the energy beam (light beam 71) and to detect whether or not there are defects in the manufactured object 15 based on the surface shape of the manufactured object 15. The powder bed forming unit 5 is configured to detect whether or not there are defects in the manufactured object 15 with the first detection device 40 and, after detecting whether or not there are defects in the manufactured object 15 with the second detection device 50, supply raw material powder 30 to form a layer 8a of raw material powder 30.

[0144] According to the configuration of (17) above, the presence or absence of defects in the fabricated object 15 is detected while the energy beam (light beam 71) for fabrication is irradiated, so the inspection time can be significantly reduced. In addition, the presence or absence of defects in the fabricated object 15 can be detected by the second detection device 50 based on the surface shape of the fabricated object 15, so inspection can be performed in a relatively short time. Therefore, according to the configuration of (17) above, the inspection time of the fabricated object 15 can be suppressed. Furthermore, with the configuration described in (17) above, the presence or absence of defects can be detected by the first detection device 40 and the second detection device 50 each time a layer 8a is fabricated. This eliminates the need for non-destructive testing after the fabrication of the fabricated object 15 is complete, thereby reducing the inspection time and costs associated with the fabricated object 15.

[0145] (18) An additive manufacturing method according to at least one embodiment of the present disclosure includes the step of detecting whether or not there are defects in the manufactured object 15 by any of the manufacturing process monitoring methods described in (1) to (16) above.

[0146] According to the method described in (18) above, a high-quality molded object 15 can be obtained while suppressing the inspection time and cost required for inspection of the molded object 15. [Explanation of Symbols]

[0147] 1. 1A Three-dimensional additive manufacturing equipment (additive manufacturing equipment) 2 Base Plate 2a Drive cylinder 4 cylinders 5 Powder bed forming section 6 Beam Splitter 8 Powder bed 8a layer 9 Chambers 9a Window section 8a layer 10 Powder laying section 15 Sculptures 20. Light beam irradiation device 21 Light beam irradiation section 22 Light beam control unit 30 Raw material powder 31 Storage section 40 First detection device 41 Light detection unit 42 Light emission monitor control unit 50 Second detection device 51 Projection section 52 Imaging Department 53. Unevenness detection unit 60 Flaw detection equipment 61 Laser irradiation device 62 Laser Interferometer 63. Flaw Detection Control Unit 71 Light beam 80 Control Unit 90 Irradiation equipment for surface processing 91 Laser beam irradiation area 92 Laser beam control unit 95 Laser light

Claims

1. A step of forming a part of an object by irradiating a layer of raw material powder with an energy beam to melt and solidify the raw material powder in the layer, A first detection step for detecting the state of the molded object during the molding step, A second detection step involves measuring the surface shape of the molded object after performing the molding step, and detecting the presence or absence of defects in the molded object based on the surface shape of the molded object. Equipped with, In the first detection step, based on the emission intensity of light emitted from the fabricated object when the energy beam is irradiated in the fabrication step, the presence or absence of defects in the fabrication layer located below the uppermost fabrication layer of the fabricated object is detected, and the presence or absence of defects due to abnormalities in the fabrication state of the uppermost fabrication layer of the fabricated object is detected. Furthermore, in the first detection step, from among the multiple measured values ​​of the luminescence intensity obtained by measuring the luminescence intensity multiple times during one molding step, at least one measured value is selected as a representative value of the luminescence intensity during one molding step, in order from the measured value with the highest luminescence intensity, and the presence or absence of the defect or malfunction is detected based on the representative value and a predetermined reference value. The first detection step and the second detection step are a method for monitoring the molding process, which is performed each time the molding step is carried out.

2. In the first detection step, if the representative value is less than the threshold determined based on the reference value, it is determined that there are no defects or malfunctions, and if the representative value is equal to or greater than the threshold, it is determined that there are defects or malfunctions. A method for monitoring a molding process according to claim 1.

3. In the first detection step, if the frequency of occurrence of the representative value that exceeds the threshold when the molding step is performed multiple times is less than the specified frequency, it is determined that there are no defects or malfunctions. If the frequency of occurrence of the representative value that exceeds the threshold is equal to or greater than the specified frequency, it is determined that there are defects or malfunctions. A method for monitoring a molding process according to claim 2.

4. A step of forming a part of an object by irradiating a layer of raw material powder with an energy beam to melt and solidify the raw material powder in the layer, A first detection step for detecting the state of the molded object during the molding step, A second detection step involves measuring the surface shape of the molded object after performing the molding step, and detecting the presence or absence of defects in the molded object based on the surface shape of the molded object. Equipped with, In the first detection step, based on the emission intensity of light emitted from the fabricated object when the energy beam is irradiated in the fabrication step, the presence or absence of defects in the fabrication layer located below the uppermost fabrication layer of the fabricated object is detected, and the presence or absence of defects due to abnormalities in the fabrication state of the uppermost fabrication layer of the fabricated object is detected. The first detection step and the second detection step are performed each time the molding step is carried out. If the defect or malfunction is detected in the first detection step or the second detection step, the process involves inspecting the molded object to obtain the state of the defect or malfunction. Equipped with Methods for monitoring the molding process.

5. In the acquisition step, the condition of the defect or malfunction is acquired by the laser ultrasonic method. A method for monitoring a molding process according to claim 4.

6. A step of repairing the defect or malfunction by irradiating with the energy beam under irradiation conditions set based on the state of the defect or malfunction obtained in the above acquisition step, Equipped with, A method for monitoring a molding process according to claim 5.

7. In the aforementioned repair step, If the depth of the defect or malfunction obtained in the acquisition step is less than the specified depth, the energy beam is irradiated at the first output to repair the defect or malfunction. If the depth of the defect or malfunction obtained in the acquisition step is greater than or equal to a specified depth, the energy beam is irradiated with a second output that is greater than the first output and increases as the depth of the defect or malfunction increases, thereby repairing the defect or malfunction. A method for monitoring a molding process according to claim 6.

8. In the aforementioned repair step, If the maximum dimensions of the defect or malfunction, when viewed from above the molded object, are less than twice the beam width of the energy beam, the defect or malfunction is repaired by irradiating it with the energy beam without scanning. If the maximum dimensions of the defect or malfunction, when viewed from above the molded object, are twice or more the beam width of the energy beam, the defect or malfunction is repaired by irradiating it with the energy beam while scanning it. A method for monitoring a molding process according to claim 6.

9. A step of forming a part of an object by irradiating a layer of raw material powder with an energy beam to melt and solidify the raw material powder in the layer, A first detection step for detecting the state of the molded object during the molding step, A second detection step involves measuring the surface shape of the molded object after performing the molding step, and detecting the presence or absence of defects in the molded object based on the surface shape of the molded object. Equipped with, In the first detection step, based on the emission intensity of light emitted from the fabricated object when the energy beam is irradiated in the fabrication step, the presence or absence of defects in the fabrication layer located below the uppermost fabrication layer of the fabricated object is detected, and the presence or absence of defects due to abnormalities in the fabrication state of the uppermost fabrication layer of the fabricated object is detected. The first detection step and the second detection step are performed each time the molding step is carried out. If the defect or malfunction is detected in the first detection step or the second detection step, the surface of the molded object is processed by irradiating it with a beam. The step of processing the surface of the molded object includes a step of inspecting the molded object whose surface has been processed to obtain the state of the defect or malfunction, Equipped with Methods for monitoring the molding process.

10. In the second detection step, the surface shape of the molded object is measured based on an image obtained by capturing a pattern projected onto the surface of the molded object. A method for monitoring a molding process according to any one of claims 1 to 9.

11. The steps include supplying the raw material powder to form the layer, After performing the step of forming the layer, and before performing the step of fabricating, the surface shape of the layer is measured, and the presence or absence of defects in the layer is detected based on the surface shape of the layer. Equipped with A method for monitoring a molding process according to any one of claims 1 to 9.

12. If a defect is detected in the layer during the detection step, the raw material powder is supplied to form a new layer of the raw material powder. Equipped with A method for monitoring a molding process according to claim 11.

13. A powder bed forming section having a base plate on which a layer of supplied raw material powder is formed, The aforementioned layer is provided with a powder bed forming section capable of irradiating it with an energy beam, A first detection device configured to detect the state of the fabricated object during irradiation with the energy beam, A second detection device configured to measure the surface shape of the fabricated object after irradiating it with the energy beam and to detect the presence or absence of defects in the fabricated object based on the surface shape of the fabricated object, Equipped with, The first detection device is configured to detect, based on the emission intensity of light emitted from the fabricated object when the energy beam is irradiated, whether or not there are defects in the fabricated layer located below the uppermost fabricated layer of the fabricated object, and whether or not there are defects due to abnormalities in the fabrication state of the uppermost fabricated layer of the fabricated object. The powder bed forming unit is configured to detect the presence or absence of defects and malfunctions using the first detection device, and to supply the raw material powder to form a layer of raw material powder after detecting the presence or absence of defects in the molded object using the second detection device. Additive manufacturing equipment.

14. A step of detecting the presence or absence of the defect or malfunction by a method for monitoring a molding process according to any one of claims 1 to 9, A layered manufacturing method comprising the following:

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