Method for controlling the crystal structure of additively fabricated metal structures
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
- Filing Date
- 2025-01-22
- Publication Date
- 2026-08-03
Smart Images
Figure 2026125362000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a method for controlling the crystal structure of a metal laminated object.
Background Art
[0002] Patent Document 1 discloses copper powder for laminated modeling used for modeling a laminated object by a laminated modeling method. The copper powder for laminated modeling is obtained by adding 0.01% by weight or more and 0.30% by weight or less of a phosphorus element to pure copper.
[0003] Patent Document 2 discloses a method for manufacturing a metal object in which heat is supplied to metal powder using an energy beam in the presence of a shielding gas supplied around the metal powder on a base plate, and a metal layer is modeled on the base plate and the metal layers are sequentially laminated. In the method for manufacturing a metal object, when modeling the first metal layer in contact with the base plate, the mass per unit volume of the shielding gas supplied into the chamber at a temperature of 25°C and a pressure of 0.1 MPa is 1.00×10 -4 g / cm 3 ~1.3×10 -3 g / cm 3 After modeling the first metal layer, as the metal layers are sequentially laminated from the surface of the first metal layer, the mass per unit volume of the shielding gas supplied into the chamber at a temperature of 25°C and a pressure of 0.1 MPa is increased by 1.00×10 -4 g / cm 3 ~1.3×10 -3 g / cm 3The settings are changed within the specified range, and the mass per unit volume of shielding gas Gn supplied into the chamber during the nth laser irradiation is selected based on a reference table created by investigating the correlation between the reference and the mass per unit volume of shielding gas Gn that yields a suitable degree of melting or penetration depth for the reference. At least one of the following is used as the reference: temperature near the molten part of the metal powder irradiated with the laser, humidity, laser power output during the nth laser irradiation, and laser scanning speed.
[0004] Patent Document 3 discloses a manufacturing apparatus for obtaining a laminated structure by stacking multiple metal layers formed by irradiating metal powder with energy rays. The manufacturing apparatus comprises an energy ray irradiation source, a chamber, a molding stage having a powder bed of metal powder that can move vertically within the chamber, one or more temperature measuring probes for measuring the temperature of the metal layer or the laminated structure in the process of being manufactured, and one or more temperature adjustment probes for adjusting the temperature of the metal layer or the laminated structure in the process of being manufactured, wherein at least one of the temperature measuring probes and at least one of the temperature adjustment probes are embedded inside the part that constitutes the powder bed of the molding stage. [Prior art documents] [Patent Documents]
[0005] [Patent Document 1] Patent No. 7001685 [Patent Document 2] Patent No. 7343484 [Patent Document 3] Patent No. 7048799 [Overview of the project] [Problems that the invention aims to solve]
[0006] This disclosure was devised in view of the conventional circumstances described above, and aims to provide a method for controlling the crystal structure of metal additively manufactured products that can manufacture higher-density metal additively manufactured products. [Means for solving the problem]
[0007] This disclosure provides a method for manufacturing a metal additive manufacturing product having a plurality of metal layers in the height direction, using a manufacturing apparatus that manufactures metal additive manufacturing products comprising: a head for irradiating a laser beam generated by a laser oscillator to an irradiation position; a base made of a metal material having a predetermined crystal structure; and a stage on which the base is mounted, wherein the method involves repeatedly performing the steps of: placing metal powder having the same composition as the metal material constituting the base on the base; irradiating the metal powder on the base with the laser beam to form the metal layer; and lowering the stage, thereby manufacturing the metal additive manufacturing product in which the plurality of metal layers are stacked, and each of the plurality of metal layers has the predetermined crystal structure. [Effects of the Invention]
[0008] According to this disclosure, it is possible to manufacture higher-density metal additive structures. [Brief explanation of the drawing]
[0009] [Figure 1] Schematic diagram of the manufacturing apparatus according to the embodiment [Figure 2] Block diagram showing an example of the internal configuration of the irradiation control device in the manufacturing apparatus according to the embodiment. [Figure 3] A diagram showing an example of a base substrate and a metal additively fabricated object. [Figure 4] Figure 3 shows the base substrate and the AA cross-sectional view of the metal additively fabricated object, as well as an enlarged view of the AA cross-section. [Figure 5] Figure 3 shows the BB cross-section of the base substrate and the CC and DD cross-sections of the metal additively manufactured product. [Modes for carrying out the invention]
[0010] (Background leading to this disclosure) The copper powder for additive manufacturing described in Patent Document 1 reduces the thermal energy of the laser light during laser irradiation by mixing phosphorus with the copper powder, thereby enabling the production of high-density, high-electrically-conductive additively manufactured objects. However, additively manufactured objects produced by mixing additives with the additive manufacturing material (in this case, copper powder) generally have the problem of not achieving the same mechanical strength as additively manufactured objects produced without additives.
[0011] The manufacturing method for metal molded objects described in Patent Document 2 improves energy efficiency by using a predetermined shielding gas to solve the problem of reduced mechanical strength due to heat accumulation in the metal molded object during manufacturing. Furthermore, the manufacturing apparatus described in Patent Document 3 facilitates the development of a desired metallic structure by controlling the cooling rate of the additively manufactured object. However, Patent Document 2 and Patent Document 3 have the problem of requiring specialized materials such as a predetermined shielding gas and specialized equipment such as a manufacturing apparatus with a predetermined cooling structure.
[0012] Hereinafter, with reference to the drawings as appropriate, each embodiment specifically disclosing the method for controlling the crystal structure of a metal additively manufactured product according to this disclosure will be described in detail. However, unnecessarily detailed explanations may be omitted. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily redundant and to facilitate understanding by those skilled in the art. The accompanying drawings and the following explanation are provided to enable those skilled in the art to fully understand this disclosure and are not intended to limit the subject matter described in the claims.
[0013] First, with reference to Figure 1, the manufacturing apparatus 1 for metal additive manufacturing will be described. Although the manufacturing apparatus 1 will be described from here on, the following description may be interpreted as a description of the manufacturing method. Figure 1 is a schematic diagram of the manufacturing apparatus 1 according to an embodiment. The manufacturing apparatus 1 for metal additive manufacturing according to this disclosure employs, for example, a powder bed method for manufacturing.
[0014] The manufacturing apparatus 1 of the metal laminated object shown in Fig. 1 includes chambers 10A and 10B, a stage 11, a base substrate 12, and a squeegee 13. The chambers 10A and 10B are housings in which the shaping (manufacturing) of the metal laminated object is performed. The chamber 10B is configured such that the laser beam LS can pass through. Also, the chambers 10A and 10B may be configured to be filled and purged with an inert gas such as argon or nitrogen, or to reduce the pressure to achieve a vacuum state, in order to prevent oxidation of the metal laminated object. The stage 11 has a base substrate 12 on which the metal lamination shaping is performed on the upper surface. The base substrate 12 is spread with the metal powder 15, which is the material of the metal laminated object, to a predetermined thickness (for example, 20 μm to 300 μm) by the squeegee 13.
[0015] The stage 11 mounts the base substrate 12 and is configured to be able to move up and down in the vertical direction. For this reason, after the laser beam described later irradiates the metal powder 15, the stage 11 and the base substrate 12 descend by a predetermined distance by a control mechanism (not shown) provided in the manufacturing apparatus 1 of the metal laminated object. Thereby, the manufacturing apparatus 1 of the metal laminated object can manufacture a metal laminated object in which metal layers are laminated by repeating the spreading of the metal powder 15, the irradiation of the laser beam, and the descent of the stage 11 and the base substrate 12. Note that the mechanism for moving up and down may be any general mechanism that is already known.
[0016] The base substrate 12 makes the thickness of the spread metal powder 15 uniform and constant as the squeegee 13 moves in the left - right direction of Fig. 1. The metal powder 15 is supplied periodically in accordance with the irradiation of the laser beam LS and the lift - down control of the stage 11.
[0017] The metal powder 15 is a so-called high-purity metal, such as copper, iron, nickel, titanium, aluminum, gold, silver, platinum, tungsten, etc. Iron with a purity of 99.9% or more is called pure iron, and examples include electrolytic iron, high-purity iron, etc. Also, copper with a purity of 99.9% or more is called pure copper, and examples include oxygen-free copper, tough pitch copper, or phosphor-deoxidized copper, etc. Furthermore, nickel with a purity of 99.0% or more is called pure nickel, and examples include nickel 200, nickel 201, etc. Note that the average particle size of the metal powder is not particularly limited, and for example, it is about 0.1 μm to 300 μm. The inert gas filled and purged in the chambers 10A and 10B may be appropriately selected as the optimal one according to the type of the metal powder 15. For example, since titanium reacts with nitrogen at high temperatures, argon is used.
[0018] Also, the manufacturing apparatus 1 for the metal laminated object includes a laser oscillator 20 and a head HD. The head HD includes an optical system 21 that irradiates the laser light oscillated from the laser oscillator 20 to an arbitrary irradiation position.
[0019] The manufacturing apparatus 1 controls the irradiation position of the laser light generated by the laser oscillator 20 by driving the head HD or the optical system 21. The manufacturing apparatus 1 for the metal laminated object irradiates the laser light pinpointedly toward an arbitrary location (for example, the location where the corresponding layer of the metal laminated object is to be formed) on the upper surface of the base substrate 12 according to a program for irradiating the laser light prepared in advance. Thereby, the manufacturing apparatus 1 for the metal laminated object can irradiate the metal powder 15 disposed on the base substrate 12 or the metal powder 15 located in its upper layer while scanning the laser light. Note that the beam diameter of the laser light is 20 μm to 500 μm, and here, as an example, it is 100 μm. Also, the wavelength of the laser is 400 nm to 600 nm, and the beam parameter product (B.P.P.) is 4 or less.
[0020] The laser oscillator 20 can output laser light such as blue or green. Based on the laser light absorption characteristics of the metal used as the metal powder 15, the laser oscillator 20 outputs laser light towards the optical system 21 of the head HD. Parameters such as the wavelength, output, and scanning speed of the laser light output by the laser oscillator 20 can be arbitrarily set by the operator.
[0021] The optical system 21 controls the irradiation position or focal position of the laser beam LS irradiated onto the metal powder 15 from the laser oscillator 20, according to a pre-prepared program for irradiating the laser beam LS. If the optical system 21 is composed of a fixed optical system, the irradiation position of the laser beam LS is controlled by moving the head HD horizontally. If it is composed of a galvanometer mirror, the irradiation position of the laser beam LS can be controlled without moving the head HD.
[0022] As shown in Figure 2, the laser oscillator 20, the optical system 21, and the head HD are all electrically connected to the control unit 31 (see Figure 2). Therefore, in the metal additive manufacturing apparatus 1, the control unit 31 can arbitrarily control the direction of the laser beam irradiated onto the upper surface of the stage 11 (in other words, the base substrate 12). The metal additive manufacturing apparatus 1 can also raise and lower the stage 11 (in other words, the base substrate 12). In practice, the metal additive manufacturing apparatus 1 uses a powder bed type blue laser or green laser fusion apparatus that allows for a long working distance.
[0023] Next, the irradiation control device 30 will be described with reference to Figure 2. Figure 2 is a block diagram showing an example of the internal configuration of the irradiation control device 30 in the manufacturing apparatus 1 according to the embodiment. The irradiation control device 30 may be integrated with the manufacturing apparatus 1, or it may be configured as a separate unit that communicates with the metal additive manufacturing apparatus 1, as shown in Figure 2.
[0024] The irradiation control device 30 comprises a control unit 31, a storage unit 32, and a communication unit 33. The control unit 31, the storage unit 32, and the communication unit 33 are connected to each other via an internal bus (not shown) or the like, enabling the input and output of data signals (data).
[0025] The control unit 31 is configured using, for example, a Central Processing Unit (CPU) or a Field Programmable Gate Array (FPGA), and works in cooperation with the storage unit 32 to perform various processes and controls. Specifically, the control unit 31 refers to the programs and data held in the storage unit 32 and executes those programs to realize the functions of the irradiation control device 30.
[0026] The memory unit 32 includes, for example, Random Access Memory (hereinafter referred to as "RAM") as work memory used when executing each process of the control unit 31, and storage for storing programs and data that define the operation of the control unit 31. Data or information generated or acquired by the control unit 31 is temporarily stored in the RAM. The program that defines the operation of the control unit 31 is written to the storage.
[0027] The control unit 31 controls various operations of the metal additive manufacturing apparatus 1 and functionally includes a lifting control unit 311, an additive manufacturing control unit 312, and a head control unit 313.
[0028] The lifting control unit 311 controls the lifting and lowering of the stage 11 according to desired conditions (for example, manufacturing conditions for a metal additively manufactured object).
[0029] The stacking control unit 312 controls the stacking state of the metal additively manufactured object so that it meets the desired conditions (for example, conditions such as appearance, dimensions, and shape required for the stacking state of a pre-prepared metal additively manufactured object).
[0030] The head control unit 313 controls the position of the head HD so that the laser beam LS is aligned with an arbitrary irradiation position on the upper surface of the base substrate 12 (for example, the location where the corresponding layer of the metal additive manufacturing is formed) according to the program for irradiating the laser beam.
[0031] The memory unit 32 stores the lifting condition information 321 and the stacking condition information 322.
[0032] The lifting / lowering condition information 321 is information such as the conditions under which the lifting / lowering control unit 311 controls the lifting and lowering of the stage 11.
[0033] The lamination condition information 322 is information such as conditions related to the lamination state of the metal additively manufactured object, as determined by the lamination control unit 312.
[0034] The communication unit 33 transmits control information from the control unit 31 to the metal additive manufacturing apparatus 1 and receives information transmitted from the metal additive manufacturing apparatus 1. The communication unit 33 can also communicate with other electronic devices. Any wired or wireless communication method is acceptable. Wireless communication here refers to any of the following, such as Wi-Fi®, Bluetooth Low Energy (BLE), Matter, Z-Wave, or Zigbee.
[0035] Next, with reference to Figure 3, the metal additive manufactured object MM produced by the manufacturing apparatus 1 will be described. Figure 3 shows an example of a base substrate 12 and a metal additive manufactured object MM. Note that the shape of the base substrate 12 and the metal additive manufactured object MM shown in Figure 3 is just an example and is not limited thereto.
[0036] The base substrate 12 has the same composition as the metal powder 15 and is made of a high-purity metal (for example, pure copper, pure nickel, or pure iron), and is composed of crystal grains MG11, MG12, MG13, ..., MG1m, as shown in Figure 5. The crystal orientation of each of the crystal grains MG11 to MG1m of the base substrate 12 is, for example,
[0100] .
[0037] Furthermore, as shown in Figure 3, the base substrate 12 may have only the surface 12A, the side on which the metal powder 15 is laid, partially having the same composition as the metal powder 15, and being made of high-purity metal (for example, pure copper, pure nickel, or pure iron, etc.), and may be composed of crystal grains MG11 to MG1m as shown in Figure 5. In such a case, the base substrate 12 is composed of two base layers (i.e., surface 12A and base layer 12B) made of different materials.
[0038] Next, the metal additive manufactured object MM produced by the manufacturing apparatus 1 will be described with reference to Figures 4 and 5, respectively. Figure 4 is a cross-sectional view AA of the base substrate 12 and the metal additive manufactured object MM shown in Figure 3, and an enlarged view of the cross-sectional view AA. Figure 5 is a cross-sectional view BB of the base substrate 12 and cross-sectional views CC and DD of the metal additive manufactured object MM shown in Figure 3.
[0039] The XY plane, indicated by the X and Y axes in Figure 5, is a horizontal plane along the surface 12A. The Z axis is perpendicular to the XY plane. The Z axis direction indicates the stacking direction (height direction) in which the metal layers are stacked.
[0040] The direction of the arrow OR indicated on each crystal grain in Figure 5 indicates the crystal orientation of each crystal grain. In this disclosure, the arrow OR generally points in the direction of the X-axis. In addition, the symbols indicating the crystal grains and arrows in Figure 5 are only assigned to some of the crystal grains and arrows in order to make the figure and explanation easier to understand. Furthermore, in Figure 5, only some of the metal layers constituting the metal additive manufactured object MM (metal layers MM1, MM2) are shown, and the other metal layers are omitted from the illustration.
[0041] When the metal powder 15 is spread onto the base substrate 12 using the squeegee 13, it is irradiated with laser light LS. The metal powder 15 absorbs the energy of the irradiated laser light LS and melts (for example, the melted area 15A shown in Figure 1). The melted metal powder 15 cools over time and crystallizes to form a metal layer. Here, the manufacturing apparatus 1 can melt the metal powder 15 with a lower output of laser light LS by irradiating the metal powder 15 with a blue laser or a green laser, which have a high energy absorption rate.
[0042] In the following sections, the manufacturing process of the metal additive manufactured object MM produced by the manufacturing apparatus 1 in this disclosure will be described in detail.
[0043] The manufacturing apparatus 1 melts the metal powder 15 spread on the base substrate 12 or the surface 12A of the base substrate 12 by irradiating it with laser light LS. The molten metal powder 15 bonds to the lower layer of the base substrate 12 or the surface 12A of the base substrate 12, and crystallizes while inheriting the crystal structure of the crystal grains MG11 to MG1m that make up the base substrate 12 or the surface 12A of the base substrate 12. As a result, the manufacturing apparatus 1 can produce a metal layer MM1 having crystal grains MG21, MG22, MG23, ..., MG2m with substantially the same crystal orientation
[0100] as the crystal grains MG11 to MG1m that make up the base substrate 12 or the surface 12A of the base substrate 12. By producing a metal layer MM1 having the same crystal structure as the base substrate 12, the manufacturing apparatus 1 can form a higher density metal layer MM1.
[0044] The manufacturing apparatus 1 melts the metal powder 15 spread on the metal layer MM1 by irradiating it with laser light LS. The molten metal powder 15 combines with the underlying metal layer MM1 and crystallizes, inheriting the crystal structure of the crystal grains MG21 to MG2m that constitute the metal layer MM1. As a result, the manufacturing apparatus 1 can produce a metal layer MM2 having crystal grains MG31, MG32, MG33, ..., MG3m with substantially the same crystal orientation
[0100] as the crystal grains MG21 to MG2m that constitute the metal layer MM1. By producing a metal layer MM2 having the same crystal structure as the metal layer MM1, the manufacturing apparatus 1 can form a higher density metal layer MM2.
[0045] The manufacturing apparatus 1 repeats the above process N times (N: an integer of 2 or more) to form a metal additive manufacturing object MM in which N metal layers are stacked.
[0046] As described above, the manufacturing apparatus 1 can form a metal additive manufacturing object MM in which multiple metal layers having the same crystal structure as the crystal grains MG11 to MG1m of the surface 12A are stacked, by repeatedly spreading the metal powder 15, irradiating the metal powder 15 with laser light LS, and lowering the stage 11 and base substrate 12.
[0047] As a result, the manufacturing apparatus 1 can more easily produce higher-density metal additive manufactured objects MM using conventional manufacturing equipment. Furthermore, if the crystal orientations of the crystal grains MG11 to MG1m on the surface 12A of the base substrate 12 are different, the crystal grains MG21 to MG2m will inherit the crystal orientation of each crystal grain, and if the surface 12A of the base substrate 12 is a single crystal, the metal additive manufactured object MM will be a single crystal. In this embodiment, a manufacturing apparatus employing the powder bed method has been described, but it is also applicable to manufacturing apparatus employing other methods such as the deposition method.
[0048] (Note) The following technologies are disclosed based on the above description of embodiments.
[0049] (Technology 1) A head HD that irradiates the laser beam LS generated by the laser oscillator 20 onto the irradiation position, A base (base substrate 12 or surface 12A of the base substrate 12) made of a metallic material having a predetermined crystal structure (for example, pure copper, pure nickel, or pure iron, etc.), A manufacturing apparatus 1 for manufacturing a metal additive manufacturing product MM having a stage 11 on which the base is mounted, and having a plurality of metal layers MM1, MM2, ... in the height direction, wherein the apparatus performs a method for manufacturing a metal additive manufacturing product MM, The steps include placing a metal powder 15 having the same composition as the metal material constituting the base onto the base, The process involves repeatedly performing the steps of irradiating the metal powder 15 on the base with the laser beam LS to form the metal layer, and lowering the stage 11, thereby manufacturing the metal additive manufacturing product MM in which the plurality of metal layers MM1, MM2, ... are stacked. Each of the plurality of metal layers MM1, MM2, ... has the predetermined crystal structure. A method for manufacturing additively fabricated metal structures (MM). As a result, the manufacturing apparatus 1 can produce a metal additive manufacturing product MM composed of metal layers MM1 and MM2 having crystal grains MG21 to MG2m and MG31 to MG3m having substantially the same crystal orientation as the crystal grains MG11 to MG1m that constitute the base substrate 12 or the surface 12A of the base substrate 12. The manufacturing apparatus 1 can form a higher density metal additive manufacturing product MM by generating metal layers MM1, MM2, ... having the same crystal structure as the surface 12A of the base substrate 12.
[0050] (Technology 2) The predetermined crystal structure has substantially the same crystal orientation as the metal material. A method for manufacturing a metal additive manufacturing product MM as described in (Technology 1). As a result, the manufacturing apparatus 1 can produce multiple metal layers MM1, MM2, ... having substantially the same orientation as the crystal grains MG11 to MG1m that constitute the base substrate 12 or the surface 12A of the base substrate 12. By generating metal layers MM1 and MM2 composed of crystal grains MG21 to MG2m and MG31 to MG3m having substantially the same orientation, the manufacturing apparatus 1 can produce a metal additively fabricated object MM having substantially the same metallic properties as the base substrate 12 or the surface 12A of the base substrate 12.
[0051] (Technology 3) When the metal material is pure copper, the laser beam LS is a blue laser. A method for manufacturing a metal additive manufacturing product MM as described in (Technology 1). Here, pure copper exhibits a higher absorption rate for blue lasers. As a result, the manufacturing apparatus 1 can efficiently melt the metal powder 15 (pure copper) at a lower power output by using a blue laser. In other words, the manufacturing apparatus 1 can more effectively suppress the decrease in the mechanical strength of the metal additive manufactured object MM caused by heat accumulation in the metal structure (multiple metal layers MM1, MM2, ...) during the manufacturing process. Furthermore, when the beam parameter product (BPP) is 4 or less, irradiation can be performed with a narrow beam diameter of, for example, about 100 μm, resulting in a high energy density per unit area, and the metal powder 15 (pure copper) can be melted without preheating the base substrate 12. In other words, the manufacturing apparatus 1 can be further simplified. This method of manufacturing metal additive manufactured objects without preheating the base substrate 12 is applicable not only to pure copper but also to metals with high thermal conductivity and high absorption rates, such as gold and silver.
[0052] Under the specific conditions of a laser center wavelength of 440 nm, laser output of 350 W, laser scanning speed of 200 mm / s, laser beam diameter of 100 μm, and base substrate temperature of 24 °C, the density was 99.75%.
[0053] (Technology 4) When the metal material is pure copper, the laser beam LS is a green laser. A method for controlling the crystal structure of a metal additively fabricated object MM as described in (Technology 1). Here, pure copper exhibits a higher absorption rate for green lasers. As a result, the manufacturing apparatus 1 can efficiently melt the metal powder 15 (pure copper) at a lower power output by using a green laser. In other words, the manufacturing apparatus 1 can more effectively suppress the decrease in the mechanical strength of the metal additive manufactured object MM caused by heat accumulation in the metal structure (multiple metal layers MM1, MM2, ...) during the manufacturing process. Furthermore, when the beam parameter product (BPP) is 4 or less, irradiation can be performed with a narrow beam diameter of, for example, about 100 μm, resulting in a high energy density per unit area, and the metal powder 15 (pure copper) can be melted without preheating the base substrate 12. In other words, the manufacturing apparatus 1 can be further simplified. This method of manufacturing metal additive manufactured objects without preheating the base substrate 12 is applicable not only to pure copper but also to metals with high thermal conductivity and high absorption rates, such as gold and silver.
[0054] (Technology 5) When the metal material is pure nickel, the laser beam LS is a blue laser. A method for controlling the crystal structure of a metal additively fabricated object MM as described in (Technology 1). Here, pure nickel exhibits a higher absorption rate for blue lasers. As a result, the manufacturing apparatus 1 can efficiently melt the metal powder 15 (pure nickel) at a lower power output by using a blue laser. In other words, the manufacturing apparatus 1 can more effectively suppress the decrease in the mechanical strength of the metal additive manufactured object MM caused by heat accumulation in the metal structure (multiple metal layers MM1, MM2, ...) during the manufacturing process.
[0055] (Technology 6) When the metal material is pure nickel, the laser beam LS is a green laser. A method for manufacturing a metal additive manufacturing product MM as described in (Technology 1). Here, pure nickel exhibits a higher absorption rate for green lasers. As a result, the manufacturing apparatus 1 can efficiently melt the metal powder 15 (pure nickel) at a lower power output by using a green laser. In other words, the manufacturing apparatus 1 can more effectively suppress the decrease in the mechanical strength of the metal additive manufactured object MM caused by heat accumulation in the metal structure (multiple metal layers MM1, MM2, ...) during the manufacturing process.
[0056] Although various embodiments have been described above with reference to the attached drawings, this disclosure is not limited to such examples. It will be clear to those skilled in the art that various modifications, alterations, substitutions, additions, deletions, and equivalents can be conceived within the scope of the claims, and these will also be understood to fall within the technical scope of this disclosure. Furthermore, the components of the various embodiments described above can be combined arbitrarily without departing from the spirit of the invention. [Industrial applicability]
[0057] This disclosure is useful as a method for controlling the crystal structure of metal additively manufactured products in order to produce higher density metal additively manufactured products. [Explanation of symbols]
[0058] 1 Manufacturing equipment 10A, 10B Chamber 11 stages 12 base board 12A surface 12B Base Layer 13 squeegee 15 Metal powder 20 Laser Oscillators 21 Optical system 30 Irradiation control device 31 Control Unit 32 Storage section 33 Communications Department 311 Lifting and lowering control unit 312 Stacked Control Unit 313 Head control unit 321 Lifting Conditions Information 322 Lamination Condition Information HD Head LS laser light MG11,MG12,MG13,MG1m,MG21,MG22,MG23,MG2m,MG31,MG32,MG33,MG3m Grain MM Metal Additive Manufacturing MM1,MM2 Metal layer
Claims
1. A head that irradiates the laser beam generated by the laser oscillator onto the irradiation position, A base made of a metallic material having a predetermined crystal structure, A method for manufacturing a metal additive manufacturing product, comprising a stage on which the base is mounted, and a manufacturing apparatus for manufacturing a metal additive manufacturing product having a plurality of metal layers in the height direction, The steps include placing a metal powder having the same composition as the metal material constituting the base onto the base, The process involves repeatedly performing the steps of irradiating the metal powder on the base with the laser light to form the metal layer, and lowering the stage, thereby manufacturing the metal additive manufacturing product in which the plurality of metal layers are stacked. Each of the plurality of metal layers has the predetermined crystal structure, A method for controlling the crystal structure of a metal additively fabricated object.
2. The predetermined crystal structure has substantially the same crystal orientation as the metal material. A method for controlling the crystal structure of a metal additively manufactured product according to claim 1.
3. If the metal material is pure copper, the laser light is a blue laser. A method for controlling the crystal structure of a metal additively manufactured product according to claim 1.
4. When the metal material is pure copper, the laser light is a green laser. A method for controlling the crystal structure of a metal additively manufactured product according to claim 1.
5. If the metal material is pure nickel, the laser light is a blue laser. A method for controlling the crystal structure of a metal additively manufactured product according to claim 1.
6. When the metal material is pure nickel, the laser light is a green laser. A method for controlling the crystal structure of a metal additively manufactured product according to claim 1.