Method and device for manufacturing metal laminated shaped article

Abstract

To make metal powder after dissolution easily accumulate in a desired dimension while forming irregular parts on a base so that the metal powder after dissolution is easily accumulated.SOLUTION: A method for manufacturing a metal laminated shaped article is such a method where metal powder 15 disposed on the top surface of a base for every layer is irradiated with laser light, and comprises: a process for irradiating the surface of the base with laser light to form irregular parts before the metal powder is disposed on the top surface; a process for disposing the metal powder to the irregular parts; and a process for irradiating the laser light to the metal powder disposed on the irregular parts. The irregular parts are formed so as to correspond to a shape of a lowest layer of the metal laminated shaped article formed on the top surface of the base.SELECTED DRAWING: Figure 4

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 discloses a powder bed printing method, a three-dimensional printing technique in which a predetermined two-dimensional shape is formed in powder by heating the powder according to a predetermined shape. In this powder bed printing method, a layer of powder is bonded to a predetermined shape, and then an additional layer of powder is applied on the bonded layer, and this process is repeated until a three-dimensional object is completed. Similarly, a method (powder bed printing) has been proposed in which a laser beam is irradiated onto metal powder spread on a base, melting the irradiated metal powder and layering it to create a shaped object. A technology has also been proposed in which unevenness is formed on the entire top surface of the base by chemical etching or the like to facilitate deposition of the melted metal powder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7320351 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure has been devised in consideration of the above-mentioned conventional circumstances, and aims to form irregularities on the base to facilitate the deposition of molten metal powder in the desired dimensions. [Means for solving the problem]

[0005] The present disclosure provides a method for manufacturing a metal additive manufacturing object by irradiating laser light onto metal powder that is arranged on the upper surface of a base, layer by layer, the method comprising the steps of: irradiating the surface of the base with the laser light to form an uneven portion before the metal powder is arranged on the upper surface; arranging the metal powder in the uneven portion; and irradiating the laser light onto the metal powder arranged in the uneven portion, wherein the uneven portion is formed to match the shape of the bottom layer of the metal additive manufacturing object that is formed on the upper surface of the base. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to form irregularities on the base to facilitate deposition of the molten metal powder, and to facilitate deposition of the molten metal powder in a desired size. [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] FIG. 10 is a diagram showing an example of the relationship between the uneven portion and the deposit in a comparative example. [Figure 4] FIG. 10 is a diagram showing an example of the relationship between the uneven portion and the deposit according to the embodiment; [Figure 5] FIG. 10 is a diagram showing an example of the relationship between the concave and convex portions and the design line according to the present embodiment; [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 three-dimensional printing technique described in Patent Document 1 involves bonding layers of powder into a predetermined shape, then applying additional layers of powder onto the bonded layers, and repeating this process until the three-dimensional object is completed, thereby creating a desired object. A similar concept can also be used to create metal objects using the powder bed method. In this case, an uneven surface is formed on the entire top surface of the base on which the metal powder is placed (spread). This facilitates the deposition of the melted metal powder. However, these uneven surfaces can cause the metal powder particles to be pulled by heat and surface tension when melted by a laser, which can easily result in uncontrollable errors in the desired deposition dimensions. As a result, there is a problem of a tendency for manufacturing precision to decrease.

[0009] Therefore, in the embodiments shown below, an example of a method and apparatus for manufacturing a metal additive manufacturing object is described, in which unevenness is formed on the base to facilitate deposition of the molten metal powder, and the molten metal powder is easily deposited in the desired dimensions.

[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, which includes 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 on 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 stage 11 is not necessarily required, and the base 12 may serve as the stage 11. An uneven portion 16 (see FIG. 4) is formed on the base by laser irradiation.

[0013] The base 12 and the stage 11 are fixed to the rotating unit 14 by, for example, two support shafts. Therefore, when a laser beam (described later) is irradiated, 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 as well. 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 , ensuring that the thickness of the spread metal powder 15 is uniform. The metal powder 15 is supplied periodically. 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, and alloys thereof. The particle size of the metal powder is also not particularly limited. For example, it is set to about 0.1 to 300 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 to 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) according to 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 a layer above it while scanning the laser beam. The metal powder 15 at the location irradiated by the laser melts, and multiple layers are stacked to form a three-dimensional metal additive manufacturing object. The laser beam irradiation width is 20 μm to 500 μm. Here, 50 μm is used as an example. The laser beam 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 and reflectors such as mirrors.

[0016] As shown in FIG. 2, the laser oscillator 29 and the optical system 21 of the metal additive manufacturing apparatus 1 are both electrically connected to a control unit 31 (see FIG. 2) of an irradiation control device 30. Therefore, in the metal additive manufacturing apparatus 1, the control unit 31 can arbitrarily control the irradiation direction 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 stereolithography device, which 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, a layering control unit 312, a concave-convex portion formation control unit 313, and an object formation control unit 314.

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

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

[0024] The uneven portion formation control unit 313 controls, for example, the laser oscillator 20, the optical system 21, the rotating unit 14, and the like for forming the uneven portion 16 (see FIG. 4) on the upper surface of the base 12.

[0025] The object formation control unit 314 controls, for example, the laser oscillator 20, the optical system 21, the rotation unit 14, and the like for forming the metal additive manufacturing object.

[0026] The storage unit 32 stores concave-convex portion formation information 321 and object formation information 322 .

[0027] The uneven portion formation information 321 is information necessary for the uneven portion formation control unit 313 to form the uneven portion 16 based on the design conditions, setback conditions, etc. of the metal object, and indicates the size, position, etc. of the uneven portion 16. The setback conditions will be described later.

[0028] The object formation information 322 is information necessary for the object formation control unit 314 to form an object, and indicates the design conditions, design lines, size, position, etc. of the object. The design lines will be described later.

[0029] 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.

[0030] Next, the relationship between the concave-convex portion and the deposit formed after the metal powder 15 is melted by the laser light will be described with reference to Fig. 3 and Fig. 4. Fig. 3 is a diagram showing an example of the relationship between the concave-convex portion and the deposit in a comparative example. Fig. 4 is a diagram showing an example of the relationship between the concave-convex portion and the deposit according to the present embodiment.

[0031] FIG. 3(a) shows a comparative example in which, as in the past, unevenness 16 is formed over the entire base 12 by chemical etching or the like. In this case, as shown in FIG. 3(b), the unevenness 16 formed over the entire base 12 allows the metal powder 15 to be stably positioned over the entire base 12. As shown in FIG. 3(c), when a laser beam with a width of, for example, about 50 μm is irradiated onto a design line (i.e., the boundary line along which the laser beam should be applied (i.e., irradiated) to form a metal additive manufacturing object; the same applies below), the laser beam irradiation may affect an area within that width slightly outside the design line. As a result, as shown in FIG. 3(d), a deposit formed after melting by the laser beam may be formed outside the design line.

[0032] On the other hand, in this embodiment, as shown in FIG. 4(a), the uneven portion 16 is formed only inside the design line. In this case, as shown in FIG. 4(b), the metal powder 15 is stably arranged inside the design line, and the metal powder 15 is unlikely to remain in areas outside the design line where the uneven portion 16 is not formed. When the design line is irradiated with laser light as shown in FIG. 4(c), the laser light irradiation affects only the area substantially inside the design line. As a result, as shown in FIG. 4(d), the deposit formed after melting by the laser light is shaped to match the design line, and the deposit is unlikely to form outside the design line. This allows the base to be uneven so that the melted metal powder can be easily deposited, while also allowing the melted metal powder to be easily deposited in the desired dimensions.

[0033] In this way, the metal additive manufacturing apparatus 1 is an apparatus 1 for manufacturing a metal additive manufacturing product manufactured by irradiating metal powder 15 with laser light for each layer, and includes a base 12 on whose upper surface the metal powder 15 is arranged, and a laser oscillator 20 that irradiates the surface of the base 12 with laser light to form an uneven portion 16 before the metal powder 15 is arranged on the upper surface, and the laser oscillator 20 is configured to irradiate the metal powder 15 arranged on the uneven portion 16 with laser light, so that the uneven portion 16 is formed to match the shape of the bottom layer of the metal additive manufacturing product to be formed on the upper surface of the base 12. In this way, the uneven portion 16 is formed on the base 12 to facilitate deposition of the melted metal powder 15, and the melted metal powder is also facilitated to deposit in the desired dimensions.

[0034] Next, the position where the concave-convex portion 16 is formed and the setback conditions will be described in detail with reference to FIG. 5. FIG. 5 is a diagram showing an example of the relationship between the concave-convex portion and the design line according to this embodiment. As a setback condition, as shown in FIG. 4, the concave-convex portion 16 may be formed in accordance with the design line, or may be formed by being set back only a certain distance inward from the design line. Here, since the size of the metal powder 15 is about 50 μm, the concave-convex portion 16 is formed in a range set back (offset further inward) from the design line by about half that amount, 1 to 25 μm. By providing a setback in this way, it is possible to manufacture a metal shaped object that is more closely aligned with the design line.

[0035] Next, the flow of the manufacturing method will be described with reference to Fig. 6. Fig. 6 is a flow diagram showing the method for manufacturing a metal additive manufacturing object according to this embodiment. Note that the order of the flow may be reversed.

[0036] As shown in FIG. 6, the base 12 is irradiated with laser light from a laser oscillator 20 to form a concave-convex portion 16 in accordance with the shape of the bottom layer (the layer in contact with the base 12) of the metal additive manufacturing object to be manufactured. The location of the laser light irradiation is aligned with the design line or formed slightly inside the design line by providing a setback (step St1). After the concave-convex portion 16 is formed, metal powder 15 is spread mainly on the concave-convex portion 16 of the base 12 (step St2). Then, laser light is irradiated from the laser oscillator 20 onto the metal powder 15 arranged on the concave-convex portion 16 (step St3). This process is repeated to stack multiple layers, thereby manufacturing a metal additive manufacturing object.

[0037] That is, the method for manufacturing a metal additive manufacturing product is a method for manufacturing a metal additive manufacturing product by irradiating metal powder 15 arranged on the upper surface of base 12 with laser light for each layer, and includes at least the steps of: irradiating the surface of base 12 with laser light to form concave-convex portions 16 before the metal powder 15 is arranged on the upper surface; arranging metal powder 15 on concave-convex portions 16; and irradiating metal powder 15 arranged on concave-convex portions 16 with laser light, wherein concave-convex portions 16 are formed to match the shape of the bottom layer of the metal additive manufacturing product to be formed on the upper surface of base 12. In this way, concave-convex portions 16 are formed on base 12 to facilitate deposition of metal powder 15 after melting, and also facilitate deposition of the metal powder after melting in the desired dimensions.

[0038] Furthermore, the uneven portion 16 may be formed at a position set back from the shape of the bottom layer of the metal additive manufacturing object formed on the upper surface of the base 12. This allows the uneven portion 16 to be formed on the base 12 so that the melted metal powder 15 can be easily deposited, and also enables the melted metal powder to be deposited with dimensions that are more in line with the design line.

[0039] 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.

[0040] <About the technology of the present disclosure> As described above, the present disclosure discloses the following technical ideas.

[0041] (Item 1) A method for manufacturing a metal additive manufacturing object by irradiating a laser beam onto metal powder (15) arranged on an upper surface of a base (12) for each layer, comprising: a step of irradiating the surface of the base (12) with the laser light to form an uneven portion (16) before the metal powder (15) is placed on the upper surface; a step of disposing the metal powder (15) on the uneven portion (16); and irradiating the metal powder (15) arranged in the uneven portion (16) with the laser light, The uneven portion (16) is formed to match the shape of the bottom layer of the metal additive manufacturing object formed on the top surface of the base (12). A method for manufacturing metal additive manufacturing objects. This allows the base 12 to have an uneven portion 16 so that the metal powder 15 can be easily deposited after melting, and also allows the metal powder to be easily deposited in a desired size after melting.

[0042] (Item 2) the concave-convex portion (16) is formed at a position set back from the shape of the lowest layer of the metal additive manufacturing object formed on the upper surface of the base (12). Item 1. A method for manufacturing a metal additive manufacturing object. This allows the base 12 to have the uneven portion 16 formed thereon to facilitate deposition of the molten metal powder 15, while also enabling deposition of the molten metal powder in dimensions more in line with the design line.

[0043] (Item 3) An apparatus for manufacturing a metal additive manufacturing object manufactured by irradiating metal powder (15) with laser light layer by layer, a base (12) on whose upper surface metal powder (15) is disposed; a laser oscillator (20) for irradiating the surface of the base (12) with the laser light to form an uneven portion (16) before the metal powder (15) is placed on the upper surface, The laser oscillator (20) irradiates the metal powder (15) arranged in the concave-convex portion with the laser light, The uneven portion (16) is formed to match the shape of the bottom layer of the metal additive manufacturing object formed on the top surface of the base (12). Manufacturing equipment for metal additive manufacturing. This allows the base 12 to have an uneven portion 16 so that the metal powder 15 can be easily deposited after melting, and also allows the metal powder to be easily deposited in a desired size after melting.

[0044] 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]

[0045] The present disclosure is useful as a method and apparatus for manufacturing a metal additive manufacturing object that can form uneven portions on a base to facilitate deposition of molten metal powder, while also enabling the molten metal powder to be deposited in the desired dimensions. [Explanation of symbols]

[0046] 1. Metal additive manufacturing equipment 10 chambers 11 Stages 12 base 13 Leveling section 14 Rotating part 15 Metal powder 16 Uneven part 20 Laser oscillator 21 Optical system 30 Irradiation control device 31 Control Unit 311 Rotation control unit 312 Stacking control unit 313 Concave and convex part formation control section 314 Modeling control unit 32 Storage section 321 Uneven part formation information 322 Information on sculpture creation

Claims

1. A method for manufacturing a metal additive manufacturing object by irradiating a laser beam onto metal powder that is arranged on an upper surface of a base for each layer, comprising: a step of irradiating the surface of the base with the laser light to form an uneven portion before the metal powder is placed on the upper surface; disposing the metal powder on the uneven portion; and irradiating the metal powder disposed in the concave-convex portion with the laser light, the concave-convex portion is formed to match the shape of the bottom layer of the metal additive manufacturing object formed on the top surface of the base. A method for manufacturing metal additive manufacturing objects.

2. the concave-convex portion is formed at a position set back from the shape of the lowest layer of the metal additive manufacturing object formed on the upper surface of the base. The method for manufacturing a metal additive manufacturing object according to claim 1 .

3. An apparatus for manufacturing a metal additive manufacturing object manufactured by irradiating metal powder with laser light layer by layer, a base on which the metal powder is disposed; a laser oscillator that irradiates the surface of the base with the laser light to form an uneven portion before the metal powder is placed on the upper surface, the laser oscillator irradiates the metal powder disposed in the concave-convex portion with the laser light, the concave-convex portion is formed to match the shape of the bottom layer of the metal additive manufacturing object formed on the top surface of the base. Metal additive manufacturing equipment.

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