Method and device for manufacturing metal laminate molding

Abstract

To facilitate maintaining the quality of a molding regardless of the radius size of the molding in manufacture of a generally spiral-shaped molding by powder bedding.SOLUTION: A method for manufacturing a metal laminate molding which a generally spiral-shaped laminate molding having a plurality of layers in a height direction. Metal powder is irradiated with laser light. An amount of deviation X in stacking of the plurality of layers of post-irradiation metal powder, which is the metal powder irradiated with laser light, is X<(√2 / 2)×A, where A is a laser spot diameter of laser light.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a method and apparatus for manufacturing a metal additive manufacturing object. [Background technology]

[0002] Patent Document 1 describes a photolithography method in which a liquid photocurable resin supported on a stage is irradiated with light to harden the photocurable resin into a desired shape. Similarly, a method (powder bed method) has been proposed in which a laser is irradiated onto metal powder spread on a stage, and the irradiated metal powder is melted to produce a shaped object. In this method, for example, a spiral-shaped object can be produced by rotating the stage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4128292 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure has been devised in consideration of the above-described conventional circumstances, and aims to make it easier to maintain the quality of a roughly spiral-shaped object when manufacturing it using a powder bed method, regardless of the radius size of the object. [Means for solving the problem]

[0005] The present disclosure provides a method for manufacturing a metal additive manufacturing object having a generally spiral shape with multiple layers in the height direction, the method comprising irradiating a laser beam toward a metal powder, and a deviation amount X of the stack of multiple layers of the irradiated metal powder, which is the metal powder irradiated with the laser beam, is X<(√2 / 2)×A, where A is the laser spot diameter of the laser beam. [Effects of the Invention]

[0006] According to the present disclosure, when a substantially spiral-shaped object is manufactured by a powder bed method, the quality of the object can be easily maintained regardless of the radius size of the object. [Brief explanation of the drawings]

[0007] [Figure 1] Schematic diagram of a metal additive manufacturing device according to the present embodiment. [Figure 2] 1 is a schematic block diagram of an irradiation control device that constitutes part of a manufacturing apparatus for a metal additive manufacturing object according to an embodiment of the present invention; [Figure 3] 1A and 1B are diagrams showing an example of a metal additive manufacturing object according to the present embodiment; FIG. 1A is a diagram showing an example of an upright-shaped object as a comparative example; and FIG. 1B is a diagram showing an example of a substantially spiral-shaped object. [Figure 4] FIG. 1 is a diagram illustrating the amount of misalignment of stacked layers according to the present embodiment. [Figure 5] 1A and 1B are diagrams illustrating stage rotation control according to the present embodiment; (a) a diagram showing a comparative example of a minor radius without control; (b) a diagram showing a comparative example of a major radius without control; (c) a diagram showing a comparative example of a minor radius with control; and (d) a diagram showing a comparative example of a major radius with control. [Figure 6] FIG. 1 is a flow chart showing a method for manufacturing a metal additive manufacturing object according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] (Background to this disclosure) The stereolithography method of Patent Document 1 can produce spiral-shaped objects. However, when producing a roughly spiral-shaped object, it is difficult to ensure quality depending on the radius of the object unless the rotation of the stage is controlled. For example, when the radius of an object is large, as compared to objects with small radii, the movement distance of the laser light increases as the stage rotates and the object approaches the periphery (edges), which tends to increase misalignment when the objects are stacked, resulting in a decrease in manufacturing accuracy.

[0009] Therefore, in the following embodiment, an example of a method and apparatus for manufacturing a metal additive manufacturing object will be described, which maintains the quality of the object regardless of the radius size of the object when manufacturing a substantially spiral-shaped object using the powder bed method.

[0010] Hereinafter, with reference to the drawings as appropriate, embodiments specifically disclosing a manufacturing method and a manufacturing apparatus for a metal additive manufacturing product according to the present disclosure will be described in detail. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters or redundant description of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure and are not intended to limit the subject matter recited in the claims.

[0011] First, a manufacturing apparatus for a metal additive manufacturing product will be described with reference to Fig. 1. The manufacturing apparatus will now be described, but it may also be interpreted as a description of a manufacturing method. Fig. 1 is a schematic diagram of a manufacturing apparatus for a metal additive manufacturing product according to the present embodiment. The manufacturing apparatus for a metal additive manufacturing product according to the present disclosure executes a manufacturing method that employs, for example, a powder bed method.

[0012] The metal additive manufacturing apparatus 1 shown in FIG. 1 includes a chamber 10, a stage 11, a base 12, a leveling unit 13, and a rotating unit 14. The chamber 10 is a housing in which a metal additive manufacturing object is formed. The stage 11 has a base 12 on its upper surface. The stage 11 equipped with the base 12 is where metal additive manufacturing is performed. Metal powder 15, for example, with a particle size of 44 μm and a thickness of approximately 80 μm, is spread over the upper surface of the base 12. The thickness of 80 μm is one example, and any thickness may be used, for example, in the range of 20 to 300 μm. The height of the metal powder 15 irradiated with laser light is, for example, 80 μm. The base 12 is not necessarily required; the metal powder 15 may be spread directly or indirectly over the upper surface of the stage 11.

[0013] The base 12 and the stage 11 are fixed to the rotating unit 14 by, for example, two support shafts. Therefore, when the metal additive manufacturing apparatus 1 is irradiated with a laser beam (described later), the rotating unit 14 is rotated by a control mechanism (not shown) included in the metal additive manufacturing apparatus 1, and simultaneously, the stage 11 and the base 12 rotate in the same manner. As a result, the metal additive manufacturing apparatus 1 can manufacture a spiral metal additive manufacturing object by rotating the base 12 and the stage 11. The mechanism of the rotating unit 14 may be a commonly known mechanism. The leveling unit 13 moves left and right in FIG. 1 in response to the rotation of the rotating unit 14, thereby ensuring that the thickness of the metal powder 15 spread evenly. Even when the stage is fixed, the laser beam may be irradiated as if the metal additive manufacturing object were rotating, depending on the angle of the optical system 21. The metal powder 15 is periodically supplied. The type of metal powder 15 is not particularly limited. Examples include powders of various metals such as copper, carbon, boron, magnesium, calcium, chromium, iron, manganese, molybdenum, cobalt, nickel, hafnium, niobium, titanium, and aluminum, as well as alloys thereof. The particle size of the metal powder is not particularly limited, and may be, for example, about 0.1 to 200 μm.

[0014] The metal additive manufacturing apparatus 1 also includes a laser oscillator 20 and an optical system 21, and uses a reflecting mirror in the optical system 21 to control the laser beam in any direction. The metal additive manufacturing apparatus 1 employs, for example, a well-known galvanometer system so that it can pinpoint the laser beam toward any location on the top surface of the base 12 (e.g., the location where a corresponding layer of the metal additive manufacturing object will be formed) in accordance with a pre-prepared laser beam irradiation program (not shown). This allows the metal additive manufacturing apparatus 1 to irradiate the metal powder 15 disposed on the base 12 or the metal powder 15 located in an upper layer thereof with the laser beam while scanning it. The irradiation width of the laser beam is 20 μm to 500 μm, and here, 50 μm is used as an example. The laser wavelength is 400 to 600 (nm) with a beam parameter product (BPP) of 3 or less.

[0015] The optical system 21 is not particularly limited as long as it controls the reflection position of the laser light irradiated from the laser oscillator 20 onto the metal powder 15 in accordance with a prepared program for irradiating the laser light. The optical system 21 can be composed of, for example, one or more lenses, mirrors, and other reflectors.

[0016] As shown in FIG. 2, the laser oscillator 20 and the optical system 21 are both electrically connected to a control unit 31 (see FIG. 2). Therefore, in the metal additive manufacturing apparatus 1, the control unit 31 can arbitrarily control the direction of irradiation of the laser light irradiated onto the upper surface of the stage 11 (in other words, the base 12). Furthermore, the metal additive manufacturing apparatus 1 can also rotate the stage 11 (in other words, the base 12) connected to the rotating unit 14 in conjunction with the rotation of the rotating unit 14. In practice, the metal additive manufacturing apparatus 1 uses a blue laser oscillator that allows for a long working distance.

[0017] Next, the irradiation control device 30 will be described with reference to Fig. 2. Fig. 2 is a schematic block diagram of the irradiation control device 30 constituting part of the metal additive manufacturing device 1 according to this embodiment. The irradiation control device 30 may be configured as an integrated unit with the metal additive manufacturing device 1, or may be configured as a separate unit that communicates with the metal additive manufacturing device 1 as shown in Fig. 2.

[0018] The irradiation control device 30 includes 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 so as to enable input and output of data signals (data).

[0019] The control unit 31 is configured using, for example, a central processing unit (hereinafter referred to as "CPU") or a field programmable gate array (hereinafter referred to as "FPGA"), and performs various processes and controls in cooperation with the storage unit 32. Specifically, the control unit 31 references the programs and data stored in the storage unit 32 and executes the programs to realize the functions of the irradiation control device 30.

[0020] The memory unit 32 has, for example, a random access memory (hereinafter referred to as "RAM") as a work memory used when executing each process of the control unit 31, and a storage for storing programs and data that define the operation of the control unit 31. The RAM temporarily stores data or information generated or acquired by the control unit 31. The storage has written therein programs that define the operation of the control unit 31.

[0021] The control unit 31 controls various operations of the metal additive manufacturing apparatus 1, and functionally includes a rotation control unit 311 and a layering control unit 312.

[0022] The rotation control unit 311 controls the rotation of the rotation unit 14 in accordance with conditions (for example, manufacturing conditions for a metal additive manufacturing object).

[0023] The stacking control unit 312 controls the stacking state of the metal additive manufacturing object so that it satisfies desired conditions (for example, conditions such as appearance, dimensions, and shape required for the stacking state of a pre-prepared metal additive manufacturing object). Each of these conditions will be described later.

[0024] The storage unit 32 stores rotation condition information 321 and stacking condition information 322 .

[0025] Rotation condition information 321 is information such as conditions for rotation control unit 311 to control the rotation of rotating unit 14.

[0026] The layering condition information 322 is information such as conditions for the layering control unit 312 to perform control so that the layering state of the metal additive manufacturing object satisfies desired conditions.

[0027] 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. The communication method may be any wired or wireless communication. The wireless communication here may be communication via a wireless local area network (LAN) such as Wi-Fi (registered trademark), Bluetooth Low Energy (hereinafter referred to as "BLE"), or an Internet of Things (IoT) network or protocol such as Matter, Z-Wave, or ZigBee.

[0028] Next, a generally spiral metal additive manufacturing object will be described with reference to Fig. 3. Fig. 3 is a diagram showing an example of a metal additive manufacturing object according to this embodiment. Fig. 3(a) is a diagram showing an example of an upright object as a comparative example, and Fig. 3(b) is a diagram showing an example of a generally spiral object.

[0029] In the comparative example shown in FIG. 3(a), it can be seen that a plurality of metal layers are stacked in the height direction (in other words, in the direction perpendicular to the upper surface of the base 12).

[0030] 3(b), the shape is formed in a substantially spiral shape. The substantially spiral shape does not have to be an exact spiral, but it is sufficient that at least a portion of the shape is generated to form at least a part of a spiral while the stage 11 is rotated by the rotating unit 14. Also, the spiral does not have to go all the way around.

[0031] Next, the lamination condition information 322 will be described with reference to FIG. 4. FIG. 4 is a diagram illustrating the amount of lamination misalignment according to this embodiment. If the misalignment X becomes too large when laminating the nth layer of irradiated metal powder and the n+1th layer of irradiated metal powder, the lamination may not be possible and the powder may be crushed. In order to ensure strength in the height direction, the misalignment X is adjusted so that the angle at the intersection of the horizontal line and an imaginary line extending in the direction in which the nth layer of irradiated metal powder and the n+1th layer of irradiated metal powder are adjacent to each other is 45 degrees or more. That is, the lamination condition information 322 is as follows: In the following formula, (√2 / 2) is the value of cos 45°.

[0032] X < (√2 / 2)×A

[0033] In this way, the metal additive manufacturing apparatus 1 is a manufacturing apparatus 1 for a metal additive manufacturing object having a substantially spiral shape with a plurality of layers in the height direction, and includes a stage 11 having an upper surface (i.e., base 12) that supports the metal powder 15, a rotating unit 14 that rotates the stage 11, and a laser oscillator 20 that irradiates the metal powder 15 with laser light. The relationship (rotation condition information 321) between the rotation angle θ of the rotating unit 14 when laminating the irradiated metal powder, which is the metal powder irradiated with the laser light, the radius r of the metal additive manufacturing object, and the laser spot diameter A of the laser light is as follows: r×tanθ > A / 4 and The deviation amount X of the stacking of the multiple irradiated metal powder layers (lamination condition information 322) is X < (√2 / 2)×A The radius r may be interpreted as the maximum distance from the center to the edge of the metal additive manufacturing object.

[0034] Next, the rotation condition information 321 will be described with reference to Fig. 5. Fig. 5 is a diagram illustrating stage rotation control according to this embodiment. Fig. 5(a) is a diagram illustrating a comparative example in which the minor radius is not controlled, Fig. 5(b) is a diagram illustrating a comparative example in which the major radius is not controlled, Fig. 5(c) is a diagram illustrating a comparative example in which the minor radius is controlled, and Fig. 5(d) is a diagram illustrating a comparative example in which the major radius is controlled.

[0035] In FIG. 5, the downward direction is the center of rotation, and the upward direction is the circumferential side of rotation (in other words, the end side away from the center). That is, FIG. 5 illustrates only the radial portion. FIG. 5 also illustrates the nth and n+1th layers of a portion of a metal additive manufacturing object, where n is an integer greater than or equal to 1. When the stage 11 is rotated by the rotating unit 14 at the same rotation angle regardless of the size of the metal additive manufacturing object, as shown in FIGS. 5(a) and 5(b), which are comparative examples, the nth and n+1th layers overlap in the radial direction for the most part in FIG. 5(a). However, in FIG. 5(b), there is a portion where the nth and n+1th layers do not overlap in the radial direction. As a result, the layering is not properly formed for the size of the metal additive manufacturing object in FIG. 5(b), resulting in a deterioration in the quality of the metal additive manufacturing object itself.

[0036] Therefore, in this embodiment, as shown in Figures 5(c) and 5(d), rotation condition information 321 is adopted that ensures that overlap occurs between the nth layer of irradiated metal powder, which is metal powder 15 irradiated with laser light, and the n+1th layer of irradiated metal powder, regardless of the size of the metal additive manufacturing object.

[0037] Specifically, when the rotation angle θ of the rotating unit 14 when depositing the irradiated metal powder, the radius r of the shaped object (i.e., the irradiated metal powder), and the laser spot diameter A are set as follows: r×tanθ > A / 4 For example, when the laser spot diameter A is 50 μm, r×tanθ > 12.5μm The rotation angle θ of the rotation unit 14 when layering the irradiated metal powder is the rotation angle between the nth layer of irradiated metal powder and the (n+1)th layer of irradiated metal powder. The radius r of the molded object (i.e., the irradiated metal powder) does not need to be the radius of the finished molded object, but may be the radius of the molded object in the portion that forms the spiral shape. This makes it possible to maintain overlap all the way to the circumferential side (in other words, the end side away from the center) even in Figure 5(d).

[0038] By storing the rotation condition information 321 in this way and controlling the rotation of the rotation unit 14 using the rotation control unit 311, it is possible to ensure that there is sufficient overlap between the irradiated metal powder of the nth layer and the irradiated metal powder of the (n+1)th layer, which makes it easier to maintain the quality of the molded object.

[0039] Next, the flow of the manufacturing method will be described with reference to Fig. 6. Fig. 6 is a flow diagram showing the manufacturing method of the metal additive manufacturing object according to the present embodiment. As shown in Fig. 6, metal powder 15 is spread directly or indirectly on the stage 11 of the manufacturing apparatus 1 (step St1). For example, it is preferable to spread it to a uniform thickness by using a leveling unit 13.

[0040] Next, the control unit 31 determines the rotation condition information 321 and the lamination condition information 322 in accordance with the rotation angle θ, the radius r of the object, and the laser spot diameter A of the laser light at that time (step St2).

[0041] The relationship of the laser spot diameter A of the light (rotation condition information 321) is as follows: r×tanθ > A / 4 and The deviation amount X of the stacking of the multiple irradiated metal powder layers (lamination condition information 322) is X < (√2 / 2)×A is.

[0042] Next, the control unit 31 rotates the rotation unit 14 based on the rotation condition information 321 and the lamination condition information 322 determined in step St2. Then, based on the determined rotation condition information 321 and the lamination condition information 322, the control unit 31 causes the laser oscillator 20 to emit laser light. This oscillated laser light is irradiated toward the base 12 via an optical system 21 such as a galvano system (step St4). Note that the order of steps St1 and St2 may be reversed.

[0043] That is, the method for manufacturing a substantially spiral metal additive manufacturing object having a plurality of layers in the height direction involves rotating the stage 11 having an upper surface (i.e., the base 12) that supports the metal powder 15, irradiating the metal powder 15 with laser light, and stacking the irradiated metal powder, which is the metal powder irradiated with the laser light. The relationship (rotation condition information 321) between the rotation angle θ of the stage 11 (in other words, the rotating unit 14), the radius r of the object, and the laser spot diameter A of the laser light is as follows: r×tanθ > A / 4 and The stacking deviation amount X of the plurality of layers (lamination condition information 322) is X < (√2 / 2)×A is.

[0044] For example, when the laser spot diameter A is 50 μm, the rotation condition information 321 is r×tanθ > 12.5μm This becomes:

[0045] The above manufacturing method and manufacturing device make it possible to easily maintain the quality of a substantially spiral-shaped object when manufacturing the object using the powder bed method, even if the radius size of the object changes.

[0046] <About the technology of the present disclosure> As described above, the present disclosure discloses the following technical ideas.

[0047] (Item 1) A method for manufacturing a substantially spiral metal additive manufacturing object having a plurality of layers in a height direction, comprising: A laser beam is irradiated onto the metal powder (15), The deviation amount X of the stack of the plurality of layers of the irradiated metal powder, which is the metal powder irradiated with the laser light, is X < (√2 / 2)×A and A is the laser spot diameter of the laser light. A method for manufacturing metal additive manufacturing objects. As a result, according to the method for manufacturing a metal additive manufacturing object, when manufacturing a substantially spiral-shaped object using the powder bed method, it becomes easier to maintain the quality of the object regardless of the radius size of the object.

[0048] (Item 2) A manufacturing apparatus (1) for a metal additive manufacturing object having a generally spiral shape with multiple layers in the height direction, a laser oscillator (20) that irradiates laser light toward the metal powder (15); The deviation amount X of the stack of the plurality of layers of the irradiated metal powder, which is the metal powder irradiated with the laser light, is X < (√2 / 2)×A and A is the laser spot diameter of the laser light. Metal additive manufacturing equipment. As a result, when the metal additive manufacturing device manufactures a substantially spiral-shaped object using the powder bed method, the quality of the object can be easily maintained regardless of the radius size of the object.

[0049] (Item 3) The relationship between the rotation angle θ of the stage when laminating the post-irradiation metal powder, which is the metal powder irradiated with the laser light, the maximum distance r from the center to the edge of the metal additive manufacturing object, and the laser spot diameter A of the laser light is as follows: r×tanθ > A / 4 That is, Item 1. A method for manufacturing a metal additive manufacturing object. As a result, according to the method for manufacturing metal additive manufacturing objects, when manufacturing an approximately spiral-shaped object by rotating a stage having an upper surface on which metal powder is placed using the powder bed method, it becomes easier to maintain the quality of the object regardless of the radius size of the object.

[0050] (Item 4) The relationship between the rotation angle θ of the stage when laminating the post-irradiation metal powder, which is the metal powder irradiated with the laser light, the maximum distance r from the center to the edge of the metal additive manufacturing object, and the laser spot diameter A of the laser light is as follows: r×tanθ > A / 4 That is, Item 2. A manufacturing apparatus for a metal additive manufacturing object. As a result, with the metal additive manufacturing device, when manufacturing an approximately spiral-shaped object by rotating a stage having an upper surface on which metal powder is arranged using the powder bed method, it becomes easier to maintain the quality of the object regardless of the radius size of the object.

[0051] (Item 5) The A / 4 is 12.5 μm Item 1. A method for manufacturing a metal additive manufacturing object. As a result, the method for manufacturing a metal additive manufacturing object can further improve the manufacturing quality when manufacturing a substantially spiral-shaped object using the powder bed method.

[0052] Although various embodiments have been described above with reference to the accompanying drawings, the present disclosure is not limited to such examples. It is clear that those skilled in the art can conceive of various modifications, alterations, substitutions, additions, deletions, and equivalents within the scope of the claims, and it is understood that these also fall within the technical scope of the present disclosure. Furthermore, the components of the various embodiments described above may be combined in any manner without departing from the spirit of the invention. [Industrial Applicability]

[0053] The present disclosure is useful as a method and apparatus for manufacturing a metal additive manufacturing object that can simplify maintaining the quality of a generally spiral-shaped object even when the radius size of the object changes when manufacturing the object using a powder bed method. [Explanation of symbols]

[0054] 1. Metal additive manufacturing equipment 10 chambers 11 Stages 12 base 13 Leveling section 14 Rotating part 15 Metal powder 20 Laser oscillator 21 Optical system 30 Irradiation control device 31 Control Unit 311 Rotation control unit 312 Stacking control unit 32 Storage section 321 Rotation condition information 322 Lamination condition information

Claims

1. A method for manufacturing a substantially spiral metal additive manufacturing object having a plurality of layers in a height direction, comprising: Laser light is irradiated onto the metal powder, The deviation amount X of the stack of the plurality of layers of the irradiated metal powder, which is the metal powder irradiated with the laser light, is X < (√2 / 2)×A A is the laser spot diameter of the laser light. A method for manufacturing metal additive manufacturing objects.

2. An apparatus for manufacturing a metal additive manufacturing object having a generally spiral shape having a plurality of layers in a height direction, a laser oscillator that irradiates laser light toward the metal powder; The deviation amount X of the stack of the plurality of layers of the irradiated metal powder, which is the metal powder irradiated with the laser light, is X < (√2 / 2)×A A is the laser spot diameter of the laser light. Metal additive manufacturing equipment.

3. The relationship between the rotation angle θ of a stage having an upper surface supporting the metal powder, the maximum distance r from the center to the edge of the metal additive manufacturing object, and the laser spot diameter A of the laser light when laminating the irradiated metal powder, which is the metal powder irradiated with the laser light, is as follows: r×tanθ > A / 4 That is, The method for manufacturing a metal additive manufacturing object according to claim 1 .

4. The relationship between the rotation angle θ of a stage having an upper surface supporting the metal powder, the maximum distance r from the center to the edge of the metal additive manufacturing object, and the laser spot diameter A of the laser light when laminating the irradiated metal powder, which is the metal powder irradiated with the laser light, is as follows: r×tanθ > A / 4 That is, The metal additive manufacturing apparatus according to claim 2 .

5. The A / 4 is 12.5 μm. The method for manufacturing a metal additive manufacturing object according to claim 1 .

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