METHOD FOR MANUFACTURING METAL FORMED BODY AND FORMING APPARATUS

Abstract

To provide a technology capable of forming easily a metal shaped article, in a production method of the metal shaped article by using a laser beam.SOLUTION: A production method of a metal shaped article includes a preheating step for heating in advance before melting, by a laser beam, metal powder which is a raw material for the metal shaped article, and a molding step for radiating the laser beam to the heated metal powder, after the preheating step, and forming the metal shaped article by melting and solidifying the metal powder.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a metal shaped body and a shaping apparatus. [Background technology]

[0002] Conventionally, there have been known methods for manufacturing a metal shaped body, in which a metal shaped body is formed by melting and solidifying a metal powder (for example, Non-Patent Document 1). In the method for manufacturing a metal shaped body, the metal powder is melted by irradiating it with a laser beam. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] "Technology for forming fine wires using pure copper powder," Internet<URL:http: / / www.jwri.osaka-u.ac.jp / work / laser1905.pdf> Summary of the Invention [Problem to be solved by the invention]

[0004] However, when metal powder is melted by irradiating it with laser light, metal powders such as copper powder, which have a relatively low absorption rate for laser light, are difficult to melt, and a metal shaped body may not be formed.

[0005] The present invention has been made to solve the above-mentioned problems, and aims to provide a technology that can easily form a metal structure in a method for manufacturing a metal structure that uses laser light to form a metal structure. [Means for solving the problem]

[0006] The present invention has been made to solve at least part of the above-mentioned problems, and can be realized in the following aspects.

[0007] (1) According to one aspect of the present invention, there is provided a method for manufacturing a metal shaped body, comprising: a preheating step of heating a metal powder, which is a raw material for the metal shaped body, before the metal powder is melted by a laser beam; and a shaping step of irradiating the heated metal powder with a laser beam after the preheating step to melt and solidify the metal powder to form the metal shaped body.

[0008] According to this configuration, the method for manufacturing a metal shaped body includes a preheating step of preheating the metal powder before a shaping step in which the metal powder is irradiated with laser light to melt and solidify the metal powder to form the metal shaped body. When the metal powder is heated in the preheating step, its absorption rate for laser light tends to increase, making it more likely to absorb the laser light irradiated in the shaping step. This makes the metal powder more likely to melt, making it easier to form the metal shaped body. Therefore, the metal shaped body can be easily formed.

[0009] (2) In the method for producing a metal shaped body of the above aspect, the preheating step may use pure copper powder as the metal powder, heat the pure copper powder to a temperature of 400°C or higher, and the shaping step may irradiate the heated pure copper powder with infrared laser light to melt and solidify the pure copper powder to form the metal shaped body. According to this configuration, when a metal shaped body made of pure copper, which has a low absorption rate for infrared laser light, is formed using infrared laser light, the pure copper powder is heated to a temperature of 400°C or higher in the preheating step. This results in an absorption rate for infrared laser light of 40% or higher in the pure copper powder, making it easy to form the metal shaped body. Therefore, a metal shaped body made of pure copper can be easily formed using infrared laser light, which is a relatively inexpensive laser light source.

[0010] (3) In the method for producing a metal shaped body according to the above aspect, the preheating step may include applying an alternating magnetic field to the metal powder to heat the metal powder. According to this configuration, the preheating step generates an induced current in the metal powder by applying an alternating magnetic field to the metal powder. This causes the metal powder itself to generate heat due to the induced current, allowing the metal powder to be heated efficiently. Therefore, the metal shaped body can be formed efficiently.

[0011] (4) In the method for manufacturing a metal object according to the above aspect, the shaping step may include supplying heated metal powder toward the focal point of the emitted laser light, melting and solidifying the metal powder to form a shaping layer, and stacking the shaping layers to form the metal object. According to this configuration, in the shaping step, the heated metal powder absorbs the laser light at the focal point of the laser light, melting and solidifying to form a shaping layer. This shaping layer is formed and stacked on top of an already formed shaping layer by continuously supplying heated metal powder. Because the metal object is formed by stacking shaping layers formed from continuously supplied metal powder in this way, the metal object can be formed in a relatively short time.

[0012] (5) In the method for producing a metal shaped object according to the above aspect, the preheating step may include a step of heating a carrier gas that transports the metal powder, and a step of heating the metal powder by transporting the heated carrier gas. According to this configuration, the metal powder is heated by the carrier gas that transports the metal powder toward the focal point of the laser beam. This allows the metal powder to be heated or kept warm by the carrier gas until it reaches the focal point of the laser beam, thereby suppressing a decrease in the laser beam absorption rate due to a temperature drop. This makes it easier to form a metal shaped object.

[0013] (6) In the method for manufacturing a metal shaped body according to the above aspect, the preheating step may include a step of spreading the metal powder on a base and a step of heating the metal powder spread on the base, and the shaping step may include irradiating the metal powder spread on the base with a laser beam to form the metal shaped body. According to this configuration, the metal powder is heated after being spread on the base. As a result, the metal powder spread on the base is heated with a relatively large volume, and therefore the temperature does not decrease easily. Then, in the shaping step, the metal powder spread on the base is irradiated with a laser beam, and the metal powder irradiated with the laser beam melts to form the metal shaped body. This allows for easy formation of the metal shaped body and improves the shape accuracy of the metal shaped body.

[0014] (7) According to another aspect of the present invention, there is provided a molding apparatus. The molding apparatus includes a preheating unit for preheating a metal powder, which is a raw material for a metal object, before the metal powder is melted by a laser beam, and a laser light source for irradiating the metal powder heated by the preheating unit with a laser beam to melt and solidify the metal powder to form the metal object. According to this configuration, the preheating unit heats the metal powder before it is irradiated with the laser beam. As a result, the heated metal powder has a higher absorptivity for the laser beam, and therefore is more likely to absorb the irradiated laser beam. Therefore, the metal powder is more likely to be melted by the laser beam, making it easier to form a metal object.

[0015] (8) In the object-making apparatus of the above aspect, the preheating unit may heat the pure copper powder as the metal powder so that its temperature reaches 400°C or higher, and the laser light source may emit infrared laser light as the laser light to melt the pure copper powder. According to this configuration, the preheating unit heats the pure copper powder so that its temperature reaches 400°C or higher. This increases the absorptivity of the pure copper powder for infrared laser light to 40% or higher, making the pure copper powder more likely to absorb the infrared laser light emitted by the laser light source. Therefore, a metal object made of pure copper can be easily made using infrared laser light, which is a relatively inexpensive laser light source.

[0016] (9) In the above-described modeling apparatus, the preheating unit may include a magnetic field generating unit that generates an alternating magnetic field to be applied to the metal powder. According to this configuration, when the magnetic field generating unit of the preheating unit generates an alternating magnetic field to be applied to the metal powder, an induced current is generated in the metal powder. This causes the metal powder itself to generate heat due to the induced current, thereby efficiently raising the temperature of the metal powder. Therefore, a metal modeled object can be efficiently formed.

[0017] The present invention can be realized in various forms, such as a system including a modeling device, a control method for these devices and systems, a computer program for causing these devices and systems to execute a method for manufacturing a metal model, a server device for distributing the computer program, and a non-transitory storage medium on which the computer program is stored. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram showing a schematic configuration of a molding apparatus according to a first embodiment. [Figure 2] 3 is a flowchart illustrating a method for manufacturing a metal shaped body according to the first embodiment. [Figure 3] FIG. 1 is a schematic diagram illustrating a molding process. [Figure 4]FIG. 1 is a diagram illustrating the relationship between the light absorptance and temperature in pure copper powder. [Figure 5] FIG. 10 is a schematic diagram showing a schematic configuration of a molding apparatus according to a second embodiment. [Figure 6] 10 is a flowchart illustrating a method for manufacturing a metal shaped body according to a second embodiment. [Figure 7] 1A to 1C are first schematic diagrams illustrating a method for producing a metal shaped body. [Figure 8] FIG. 10 is a second schematic diagram illustrating the method for producing a metal shaped body. [Figure 9] FIG. 10 is a schematic diagram showing a schematic configuration of a molding apparatus according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] First Embodiment FIG. 1 is a schematic diagram showing the overall configuration of a modeling apparatus 1 according to a first embodiment. The modeling apparatus 1 includes a processing head 5, a support unit 30, and a control unit 40. The modeling apparatus 1 melts and solidifies pure copper powder 6, which is a powdered raw material, to form a metal modeled object 7 made of pure copper on a surface 8a of a substrate 8. For ease of explanation, in FIG. 1, the vertical direction in the modeling apparatus 1 according to this embodiment is defined as the z-axis direction, and two orthogonal directions on a horizontal plane perpendicular to the z-axis are defined as the x-axis direction and the y-axis direction, respectively.

[0020] The processing head 5 is disposed on the positive side of the z-axis relative to the substrate 8 on which the metal structure 7 is formed. The processing head 5 includes a laser light source 10 and a raw material supply unit 20. In this embodiment, the processing head 5 is connected to a drive mechanism (not shown). The processing head 5 is movable in any of the x-axis, y-axis, and z-axis directions in response to commands from a control unit 40 electrically connected to the drive mechanism.

[0021] The laser light source 10 is a light source that emits laser light, and in this embodiment is a fiber laser oscillator that oscillates infrared laser light Lz1 having a wavelength of 1070 nm. The infrared laser light Lz1 emitted by the laser light source 10 is focused at a focusing point Fc1 on the substrate 8. The laser light source 10 is electrically connected to the control unit 40, and emits the infrared laser light Lz1 in response to commands from the control unit 40. Note that the laser light source 10 is not limited to a fiber laser oscillator, and may be a solid-state laser, a semiconductor laser, or the like.

[0022] The raw material supply unit 20 includes a raw material tank 21, a gas tank 22, a nozzle 23, and an AC power supply 24. The raw material supply unit 20 is electrically connected to a control unit 40, and supplies heated pure copper powder 6 to a focal point Fc1 of the infrared laser light Lz1 on the substrate 8 in response to a command from the control unit 40.

[0023] The raw material tank 21 stores pure copper powder 6, which is the raw material for the metal shaped body 7. Here, "pure copper powder" refers to metal powder with a copper content of 100%. The gas tank 22 stores a carrier gas, such as argon gas, which has low reactivity with the pure copper powder 6 and transports the pure copper powder 6 to the focal point Fc1 of the infrared laser light Lz1. In this embodiment, the gas tank 22 includes a heater 22a that heats the stored argon gas. The raw material tank 21 and the gas tank 22 are connected to a nozzle 23.

[0024] The nozzle 23 includes a nozzle portion 23a and a coil 23b. The nozzle portion 23a is a substantially cylindrical member and has a flow path 23c through which the pure copper powder 6 transported by the argon gas passes. The coil 23b is disposed outside the nozzle portion 23a and is electrically connected to an AC power source 24. The coil 23b generates an alternating magnetic field in the flow path 23c by AC power supplied from the AC power source 24. This generates an induced current inside the pure copper powder 6 passing through the flow path 23c, causing the temperature of the pure copper powder 6 to rise. In this embodiment, the pure copper powder 6 is transported by the argon gas heated in the gas tank 22, and is therefore also heated by this argon gas and kept warm until it reaches the focal point Fc1. The pure copper powder 6 that has passed through the nozzle portion 23a is supplied to the focal point Fc1 of the infrared laser light Lz1 together with the argon gas. The coil 23b corresponds to the "magnetic field generating unit" in the claims.

[0025] The support unit 30 supports the substrate 8 on which the metal object 7 is formed. The support unit 30 is electrically connected to the control unit 40, and is capable of moving the substrate 8 in the x-axis direction and the y-axis direction and changing the angle of the surface 8a of the substrate 8 relative to the xy plane in response to commands from the control unit 40. This allows the modeling device 1 to form metal objects 7 with various three-dimensional shapes by combining the movement of the processing head 5 and the change in the orientation of the substrate 8 by the support unit 30.

[0026] The control unit 40 is a computer including a ROM, a RAM, and a CPU. The control unit 40 controls the operation of the molding apparatus 1 based on a computer program related to the shape of the metal molded body 7, which has been input in advance. Specifically, the control unit 40 controls the timing of laser beam emission from the laser light source 10. The control unit 40 also controls the timing and amount of pure copper powder 6 supplied from the raw material tank 21, as well as the timing, amount, and temperature of argon gas supplied from the gas tank 22. The control unit 40 also controls the AC power supplied from the AC power source 24 to the coil 23b to control the strength of the alternating magnetic field generated by the coil 23b. The control unit 40 also controls the drive mechanism connected to the machining head 5 and the support unit 30, thereby controlling the movement of the machining head 5 and the attitude of the substrate 8. The control by the control unit 40 will be described in detail below.

[0027] 2 is a flowchart illustrating a method for manufacturing the metal object 7. Next, the details of the method for manufacturing the metal object 7 of this embodiment will be described. The method for manufacturing the metal object 7 of this embodiment is a method in which the modeling apparatus 1 manufactures a linear metal object 7 made of, for example, only copper on the surface 8a of the base material 8, and can be executed in response to an instruction from the operator of the modeling apparatus 1 to start manufacturing the metal object 7.

[0028] In the method for manufacturing the metal shaped body 7 of this embodiment, first, the argon gas stored in the gas tank 22 of the processing head 5 is heated (step S11: gas heating step). The raw material supply unit 20 supplies power to the heater 22a provided in the gas tank 22 in response to a command from the control unit 40. As a result, the argon gas in the gas tank 22 is heated.

[0029] Next, the pure copper powder 6 is heated (step S12: powder heating step). In response to a command from the control unit 40, the raw material supply unit 20 mixes the pure copper powder 6 stored in the raw material tank 21 with the argon gas sent from the gas tank 22 to the nozzle 23, and sends the pure copper powder 6 to the nozzle 23. The pure copper powder 6 carried by the argon gas is heated by the heat of the argon gas heated in the gas heating step.

[0030] In the nozzle 23 through which the pure copper powder 6 is fed, AC power from the AC power supply 24 is supplied to the coil 23b in response to a command from the control unit 40, thereby forming an AC magnetic field in the flow path 23c. As a result, the pure copper powder 6 passing through the flow path 23c of the nozzle 23 is heated by an induced current generated within the pure copper powder 6. In this embodiment, the control unit 40 controls the strength of the AC magnetic field formed by the coil 23b so that the temperature of the pure copper powder 6 at the focal point Fc1 of the infrared laser beam Lz1 is 400°C or higher. In this manner, in the method for producing a metal shaped body 7 of this embodiment, the pure copper powder 6 is heated by the heat of the argon gas transporting the pure copper powder 6 and the induced current due to the AC magnetic field before being irradiated with the infrared laser beam Lz1.

[0031] Next, the heated pure copper powder 6 is melted by the infrared laser beam Lz1 and then solidified to form a metal shaped body 7 (step S13: shaping process). The control unit 40 controls the movement of the processing head 5 so that the pure copper powder 6 that has passed through the flow path 23c of the nozzle 23 is sprayed together with argon gas toward the focal point Fc1 of the infrared laser beam Lz1. At the focal point Fc1 of the infrared laser beam Lz1, the pure copper powder 6 absorbs the infrared laser beam Lz1, melts, and then solidifies, thereby forming a shaped layer made of pure copper.

[0032] FIG. 3 is a schematic diagram illustrating the molding process. In the molding process, pure copper powder 6 sprayed toward the focal point Fc1 melts by absorbing the infrared laser light Fz1, forming a melt pool Pm of pure copper. When more pure copper powder 6 is added to the already formed melt pool Pm, the volume of the melt pool Pm increases, and a portion of the molten pure copper in the melt pool Pm located relatively far from the focal point Fc1 solidifies to form a molding layer L7 made of pure copper. In the molding process, as shown in FIG. 3, pure copper powder 6 is continuously added to the melt pool Pm, stacking multiple molding layers L7 to form a metal molded object 7. Note that in FIG. 3, the temperature of the metal molded object 7 is indicated by the density of hatched dots, with lower dot density indicating higher temperatures.

[0033] In the method for manufacturing the metal object 7 of this embodiment, the metal object 7 is formed on the substrate 8 in this manner. In the forming process, by changing the position of the substrate 8 or the angle of the surface 8a of the substrate 8 using the support 30, the metal object 7 can be formed in a shape that is not limited to a linear shape, but also has a spiral or circular shape that is continuously overlapping.

[0034] FIG. 4 is a diagram illustrating the relationship between the light absorptance of pure copper powder and temperature. In FIG. 4, the horizontal axis represents the temperature of the pure copper powder, and the vertical axis represents the absorptance of the pure copper powder for measurement light having a wavelength (1050 nm) that is approximately the same as the fundamental wavelength of infrared laser light, 1064 nm. The relationship between the absorptance of measurement light and the temperature of the pure copper powder shown in FIG. 4 is a value obtained through experiments. As shown in FIG. 4, when the temperature of pure copper powder is relatively low, for example, at temperatures below 300°C, the absorptance of measurement light is very low, at about several percent. Therefore, pure copper powder is considered unable to efficiently absorb irradiated infrared laser light at temperatures below 300°C, making it difficult to melt pure copper powder using infrared laser light and form a metal object made of pure copper. However, when the temperature of pure copper powder exceeds 300°C, the absorptance of measurement light increases, and it is considered that pure copper powder is more likely to absorb irradiated infrared laser light. In this embodiment, for example, by raising the temperature of the pure copper powder to 400°C or higher, the absorptivity of the infrared laser light Lz1 is increased to 40% or higher, making it possible to form a metal structure 7 made of pure copper using the infrared laser light Lz1.

[0035] The method for manufacturing the metal object 7 of this embodiment described above includes a powder heating step in which the pure copper powder 6 is preheated before the shaping step in which the pure copper powder 6 is irradiated with infrared laser light Lz1 to melt and solidify the pure copper powder 6, thereby forming the metal object 7. When the pure copper powder 6 is heated in the powder heating step, its absorptivity for the infrared laser light Lz1 increases, and the pure copper powder 6 is therefore more likely to absorb the infrared laser light Lz1 irradiated thereto in the shaping step. This makes the pure copper powder 6 more likely to melt, facilitating the formation of the metal object 7. Therefore, the metal object 7 can be easily formed from pure copper, which has low absorptivity for infrared laser light.

[0036] Furthermore, according to the method for producing the metal object 7 of this embodiment, when the infrared laser beam Lz1 is used to form the metal object 7 made of pure copper, which has a low absorptivity for the infrared laser beam Lz1, the pure copper powder 6 is heated to 400°C or higher in the powder heating step. This results in an absorptivity for the infrared laser beam Lz1 of 40% or higher in the pure copper powder 6, which makes it easier for the pure copper powder 6 to be melted by the infrared laser beam Lz1 and facilitates the formation of the metal object 7. Therefore, the metal object 7 made of pure copper can be easily formed using the infrared laser beam Lz1, which is a relatively inexpensive laser source.

[0037] Furthermore, according to the method for producing the metal shaped body 7 of this embodiment, in the powder heating step, an alternating magnetic field is applied to the pure copper powder 6, thereby generating an induced current in the pure copper powder 6. As a result, the pure copper powder 6 itself generates heat due to the induced current, and the pure copper powder 6 can be efficiently heated. Therefore, the metal shaped body 7 can be efficiently formed.

[0038] According to the manufacturing method of the metal shaped body 7 of this embodiment, in the shaping process, the heated pure copper powder 6 absorbs the infrared laser beam Lz1 at the focal point Fc1 of the infrared laser beam Lz1, melts, and solidifies to form the shaping layer L7. The shaping layer L7 is formed and stacked on top of the already formed shaping layer L7 by continuously supplying the heated pure copper powder 6. In this way, the metal shaped body 7 is formed by stacking the shaping layers L7 formed from the continuously supplied pure copper powder 6, so that the metal shaped body 7 can be formed in a relatively short time.

[0039] Furthermore, according to the method for producing the metal shaped body 7 of this embodiment, the pure copper powder 6 is heated by the argon gas that carries the pure copper powder 6 toward the focal point Fc1 of the infrared laser beam Lz1. As a result, the pure copper powder 6 is heated or kept warm by the argon gas until it reaches the focal point Fc1 of the infrared laser beam Lz1, which prevents a decrease in the absorptivity of the infrared laser beam Lz1 due to a temperature drop. This makes it even easier to form the metal shaped body 7.

[0040] Furthermore, according to the modeling apparatus 1 of this embodiment, the nozzle 23 heats the pure copper powder 6 before it is irradiated with the infrared laser beam Lz1 and melted. This increases the absorptivity of the pure copper powder 6 to the infrared laser beam Lz1, making it more likely to absorb the irradiated infrared laser beam Lz1. This makes it possible to easily form the metal model 7 using pure copper, which has a low absorptivity to the infrared laser beam Lz1.

[0041] Furthermore, according to the object-making apparatus 1 of this embodiment, the nozzle 23 heats the pure copper powder 6 so that the temperature of the pure copper powder 6 reaches 400°C or higher. This makes the absorptivity of the infrared laser light Lz1 in the pure copper powder 6 40% or higher, making the pure copper powder 6 more likely to absorb the infrared laser light Lz1 emitted by the laser light source 10. Therefore, it is possible to easily make a metal object 7 made of pure copper using the infrared laser light Lz1, which is a relatively inexpensive laser light source.

[0042] Furthermore, according to the molding apparatus 1 of this embodiment, when the coil 23b of the nozzle 23 forms an alternating magnetic field that is applied to the pure copper powder 6, an induced current is generated in the pure copper powder 6. As a result, the pure copper powder 6 itself generates heat due to the induced current, and the pure copper powder 6 can be efficiently heated. Therefore, the metal molded body 7 can be efficiently formed.

[0043] Second Embodiment 5 is a schematic diagram showing the overall configuration of a modeling apparatus according to the second embodiment. The modeling apparatus 2 according to the second embodiment is different from the modeling apparatus 1 according to the first embodiment (FIG. 1) in the configuration of the device that supports the metal modeled object.

[0044] The modeling apparatus 2 of the second embodiment includes a laser light source 10, a raw material supply unit 25, a modeling unit 50, and a control unit 40. In the modeling apparatus 2, the infrared laser light emitted by the laser light source 10 is irradiated onto a portion of the pure copper powder 6 filled in the modeling unit 50, thereby forming a metal model 7. For ease of explanation, in FIG. 5 , the vertical direction in the modeling apparatus 2 of the present embodiment is defined as the z-axis direction, and two orthogonal directions on a horizontal plane perpendicular to the z-axis are defined as the x-axis direction and the y-axis direction, respectively.

[0045] The laser light source 10 included in the molding device 2 is connected to a drive mechanism (not shown) and is arranged to be movable above the molding unit 50. The infrared laser light emitted by the laser light source 10 is focused at the position of the pure copper powder 6 spread over the molding unit 50.

[0046] The raw material supply unit 25 is a raw material tank that stores the pure copper powder 6. The raw material supply unit 25 is connected to a drive mechanism unit (not shown), and is arranged to be movable above the modeling unit 50 (white arrow F21 in FIG. 5). The raw material supply unit 25 supplies the pure copper powder 6 by dropping the pure copper powder 6 into the modeling unit 50 while moving above the modeling unit 50 (white arrow F22 in FIG. 5). In this embodiment, the raw material supply unit 25 is equipped with a heater 25a that heats the pure copper powder 6.

[0047] The molding unit 50 forms a space below the laser light source 10 and the raw material supply unit 25 in which the pure copper powder 6 supplied by the raw material supply unit 25 can be spread. The molding unit 50 includes a case unit 51, a lifting unit 52, a coil 53, and an AC power supply 54.

[0048] The case part 51 is a member having a concave shape, and has an opening 51a on the positive side in the z-axis direction through which the pure copper powder 6 supplied from the raw material supply part 25 passes. The opening 51a of the case part 51 is formed to be larger than the metal object 7 formed by the molding apparatus 2.

[0049] The lifting / lowering unit 52 is disposed in the internal space 51b of the case 51. A support surface 52a having the same area as the opening 51a of the case 51 is formed on the positive side of the lifting / lowering unit 52 in the z-axis direction. The lifting / lowering unit 52 is provided so as to be movable in the z-axis direction relative to the case 51 (white arrow F23 in FIG. 5). When the lifting / lowering unit 52 moves in the z-axis direction, the opening 51a side of the internal space 51b of the case 51 becomes a space 51c into which the pure copper powder 6 can be filled.

[0050] Coil 53 is a coil arranged to surround case portion 51. Coil 53 forms an alternating magnetic field in internal space 51b of case portion 51 by AC power supplied from AC power source 54. Coil 53 corresponds to the "magnetic field forming portion" in the claims.

[0051] The control unit 40 controls the operation of the molding apparatus 2 based on a computer program related to the shape of the metal molded body 7, which has been input in advance. Specifically, the control unit 40 controls the movement of the raw material supply unit 25 and the amount of pure copper powder 6 supplied to the space 51c, as well as the movement of the laser light source 10 and the emission timing of the infrared laser light. The control unit 40 also controls the AC power supplied to the coil 53 by the AC power supply 54 in order to control the alternating magnetic field formed in the internal space 51b of the case 51. Furthermore, the control unit 40 controls the movement of the lifting unit 52 in the molding unit 50. The details of the control by the control unit 40 will be described later.

[0052] 6 is a flowchart illustrating a method for manufacturing a metal object. Next, details of the method for manufacturing the metal object 7 of this embodiment will be described. The method for manufacturing the metal object 7 of this embodiment is a method for manufacturing a metal object 7 of any three-dimensional shape made only of copper, and can be executed in response to an instruction from the operator of the modeling apparatus 2 to start modeling the metal object 7.

[0053] In the method for manufacturing a metal shaped body 7 of this embodiment, first, pure copper powder 6 is supplied to the space 51c of the shaping unit 50 and spread out (step S21: spreading step). The control unit 40 moves the lifting unit 52 in the shaping unit 50 to form the space 51c on the opening 51a side of the shaping unit 50, into which the pure copper powder 6 heated by the heater 25a can be spread. The position of the lifting unit 52 at this time is set so that the depth of the space 51c (the distance in the z-axis direction from the opening 51a to the support surface 52a) is deep enough to melt the pure copper powder 6 on the support surface 52a with the infrared laser light emitted by the laser light source 10. After the lifting unit 52 has moved, the raw material supply unit 25 is moved to supply the pure copper powder 6 into the space 51c. After supplying the pure copper powder 6 to the space 51c, the pure copper powder 6 above the opening 51a is removed by a coater (not shown) or the like, so that the pure copper powder 6 is spread only in the space 51c. Here, the layer of pure copper powder 6 initially spread in the space 51c is referred to as a powder layer L61.

[0054] Next, the pure copper powder 6 spread in the space 51c is preheated (step S22: powder heating step). The control unit 40 supplies AC power to the coil 53 in the forming unit 50 to form an alternating magnetic field inside the case unit 51. This alternating magnetic field generates an induced current inside each of the pure copper powder particles 6 in the powder layer L61. The temperature of the pure copper powder 6 increases due to the induced current. In this embodiment, the coil 53 forms a magnetic field so that the temperature of the pure copper powder 6 becomes 400°C or higher. In this manner, in the method for producing a metal formed body 7 of this embodiment, the pure copper powder 6 is heated by the heat of the heater 25a and the induced current caused by the alternating magnetic field before being irradiated with the infrared laser light Lz1. Note that when the pure copper powder 6 is heated by the induced current, it is preferable that the area including the area around the pure copper powder 6 be filled with an inert gas atmosphere such as argon gas. Heating the pure copper powder 6 in air may cause oxidation by the oxygen in the air, which may result in oxygen being contained in the metal shaped body 7, and therefore oxidation of copper is suppressed.

[0055] Next, the pure copper powder 6 heated in the powder heating step is irradiated with an infrared laser beam to form a metal shaped body 7 (step S23: shaping step). The control unit 40 moves the laser light source 10 to focus the infrared laser beam on the pure copper powder 6 spread in the space 51c.

[0056] FIG. 7 is a first schematic diagram illustrating a method for manufacturing a metal shaped body 7. The schematic diagram in FIG. 7 illustrates the state after the formation of the first shaping layer L71, which forms the metal shaped body 7, is completed in the shaping process described above by irradiating the pure copper powder 6 with infrared laser light Lz1, melting a portion of the pure copper powder 6, and then solidifying the melted pure copper powder 6. In the shaping process, the laser light source 10 moves as indicated by the hollow arrow F24 in FIG. 7 so that the infrared laser light Lz1 irradiates a portion of the pure copper powder 6 contained in the powder layer L61 formed in the spreading process. As a result, a portion of the pure copper powder 6 contained in the powder layer L61 becomes the shaping layer L71 of the metal shaped body 7.

[0057] Returning to FIG. 6, next, it is determined whether the metal structure 7 is complete (step S24). The control unit 40 determines whether the program input in advance has ended. If the control unit 40 determines that the program has ended (step S24: YES), it ends the manufacturing process for the metal structure 7. If the control unit 40 determines that the program has not ended (step S24: NO), it returns to step S21 and again performs the laying step, heating step, and modeling step.

[0058] FIG. 8 is a second schematic diagram illustrating a method for manufacturing a metal shaped body, illustrating a shaping step performed after the shaping step described in FIG. 7. When the determination in step S24 determines that the spreading step of step S21 will be performed again, the control unit 40 moves the lifting unit 52 in the negative direction of the z axis (white arrow F25 in FIG. 8). This creates a space in which pure copper powder 6 can be spread on top of the powder layer L61, including the shaping layer L71 of the metal shaped body 7 shaped in the immediately preceding shaping step. The control unit 40 supplies pure copper powder 6 to this newly created space using the raw material supply unit 25, forming a new powder layer L62.

[0059] The control unit 40 then heats the new powder layer L62 using the coil 53. The control unit 40 then irradiates the powder layer L62 with infrared laser light Lz1 to melt and then solidify the pure copper powder 6 in the powder layer L62, thereby stacking a second shaping layer L72, which forms the metal structure 7, on top of the first shaping layer L71. In this manner, the metal structure 7 is formed in the manufacturing method of the metal structure 7 of this embodiment. In step S24 of the manufacturing method of the metal structure 7, the control unit 40 determines that the program has ended, and when the manufacturing process for this metal structure 7 is completed, the control unit 40 raises the lifting unit 52 in the positive direction of the z axis and removes the metal structure 7.

[0060] The method for manufacturing the metal object 7 of this embodiment described above includes a powder heating step of preheating the pure copper powder 6 before the shaping step of melting and solidifying the pure copper powder 6 with the infrared laser light Lz1 to form the metal object 7. This allows the pure copper powder 6 to more easily absorb the irradiated infrared laser light Lz1, making it easier to form the metal object 7. This makes it easy to form the metal object 7 using pure copper, which has a low absorptivity for the infrared laser light Lz1.

[0061] Furthermore, according to the method for manufacturing the metal shaped body 7 of this embodiment, the pure copper powder 6 is heated after being spread inside the shaping unit 50. As a result, the pure copper powder 6 spread inside the shaping unit 50 is heated at a relatively large volume, and therefore the temperature does not easily decrease. Thereafter, in the shaping step, the pure copper powder 6 spread inside the shaping unit 50 is irradiated with infrared laser light Lz1, and the pure copper powder 6 irradiated with the infrared laser light Lz1 melts, thereby forming the metal shaped body 7. This makes it possible to easily form the metal shaped body 7 and improve the shape accuracy of the metal shaped body 7.

[0062] <Third embodiment> 9 is a schematic diagram showing a schematic configuration of a modeling apparatus according to the third embodiment. The modeling apparatus 3 according to the third embodiment is different from the modeling apparatus 1 according to the first embodiment (FIG. 1) in the configuration of the raw material supply unit.

[0063] The modeling apparatus 3 of the present embodiment includes a processing head 5, a support unit 30, and a control unit 40. The processing head 5 of the present embodiment includes a laser light source 10 and a raw material supply unit 60.

[0064] The raw material supply unit 60 includes a raw material tank 21, a gas tank 22, a nozzle 63, and a power supply 64. The raw material supply unit 60 is electrically connected to the control unit 40, and supplies heated pure copper powder 6 to the focal point Fc1 of the infrared laser light Lz1 on the substrate 8 in response to a command from the control unit 40.

[0065] The nozzle 63 includes a nozzle portion 23a and a heating wire 63b. The heating wire 63b is embedded in the nozzle portion 23a and is electrically connected to a power source 64. The heating wire 63b generates heat by the power supplied from the power source 64, which increases the temperature of the nozzle portion 23a. As a result, the pure copper powder 6 passing through the flow path 23c is heated by radiant heat from the nozzle portion 23a. In this manner, in this embodiment, the pure copper powder 6 is preheated by radiant heat and then melted by the infrared laser light Lz1 to form the metal shaped body 7.

[0066] The method for manufacturing a metal object according to this embodiment, as described above, includes a powder heating step in which the pure copper powder 6 is preheated before the shaping step in which the pure copper powder 6 is melted and solidified by the infrared laser light Lz1 to form the metal object 7. In this embodiment, the powder heating step involves heating the pure copper powder 6 by radiant heat from the nozzle 63. This allows the pure copper powder 6 to more easily absorb the irradiated infrared laser light Lz1, making it easier to form the metal object 7. This makes it possible to easily form the metal object 7 using pure copper, which has a low absorptivity for the infrared laser light Lz1.

[0067] <Modification of this embodiment> The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[0068] [Variation 1] In the first embodiment, heated pure copper powder 6 is supplied to the focal point Fc1 of the infrared laser beam Lz1, where it is melted and solidified to form the metal shaped body 7. In the second embodiment, spread pure copper powder 6 is heated and then irradiated with the infrared laser beam Lz1 to melt and solidify the pure copper powder 6, thereby forming the metal shaped body 7. However, the method for producing the metal shaped body 7 from the pure copper powder 6 using the infrared laser beam Lz1 is not limited to this. Before the "shaping step" in which the infrared laser beam Lz1 is irradiated to form the metal shaped body 7, a "preheating step" in which the pure copper powder 6 is heated before being irradiated with the infrared laser beam Lz1 may be performed.

[0069] [Variation 2] In the above-described embodiments, the modeling apparatuses 1, 2, and 3 form the metal object 7 made of pure copper using infrared laser light Lz1 emitted by a fiber laser oscillator. However, the combination of the type of laser light and the raw material is not limited to this. The laser light is not limited to infrared laser light, and laser light with a wavelength different from infrared light may be used. Furthermore, the raw material of the metal object is not limited to pure copper, and may be a raw material containing copper, or a raw material containing a metal species other than copper, such as silver or gold, that has a low absorptivity for infrared laser light.

[0070] [Variation 3] In the first and second embodiments, the pure copper powder 6 is preheated by an induced current generated by applying an alternating magnetic field. However, the method for heating the pure copper powder 6 is not limited to this. As in the third embodiment, the pure copper powder 6 may be heated by radiation heating using a member forming a flow path.

[0071] [Variation 4] In the first embodiment, the pure copper powder 6 is supplied to the focal point Fc1 by argon gas. However, the method of supplying the raw material to the focal point Fc1 is not limited to this. Argon gas may not be used. For example, a wire made of the material of the metal shaped body 7 may be preheated and then supplied to the focal point Fc1. Furthermore, in the first embodiment, the argon gas that transports the pure copper powder 6 is heated before transporting the pure copper powder 6. However, the argon gas does not need to be heated, and the pure copper powder 6 may be transported at room temperature.

[0072] [Variation 5] In the second embodiment, the pure copper powder 6 is spread, heated, and then irradiated with laser light. Laser light may also be irradiated while heating. This can further suppress a decrease in the temperature of the pure copper powder 6 compared to when the pure copper powder 6 is spread, heated, and then irradiated with laser light, thereby suppressing a decrease in the absorptivity of the infrared laser light. Furthermore, in the second embodiment, the raw material supply unit 25 supplies the pure copper powder 6 by dropping the pure copper powder 6 into the shaping unit 50, but the method of supplying the pure copper powder 6 to the shaping unit 50 is not limited to this.

[0073] [Variation 6] In the second embodiment, the pure copper powder 6 is preheated by the heat of the heater 25a and the induced current due to the alternating magnetic field. However, the pure copper powder 6 may be heated only by the heat of the heater 25a or only by the induced current due to the alternating magnetic field.

[0074] This aspect has been described above based on embodiments and modifications. However, the above-described embodiments are intended to facilitate understanding of this aspect and are not intended to limit this aspect. This aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents thereof are included in this aspect. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate. [Explanation of symbols]

[0075] 1,2,3…modeling device 6…Pure copper powder 7…Metal shaped object L7,L71,L72…Building layer 52...Lifting section 10...Laser light source 23,63...Nozzle 50...Modeling department 23b, 53... Coil

Claims

1. A method for manufacturing a metal shaped body, comprising: a preheating step of preheating a metal powder that is a raw material for the metal shaped body before the metal powder is melted by a laser beam; a shaping step in which, after the preheating step, the heated metal powder is irradiated with laser light to melt and solidify the metal powder, thereby forming the metal shaped body; In the preheating step, an alternating magnetic field is applied to the metal powder moving within a nozzle that sprays the metal powder toward a focal point of the laser light, thereby heating the metal powder. A method for manufacturing a metal shaped body.

2. The method for producing a metal shaped body according to claim 1, In the preheating step, pure copper powder is used as the metal powder, and the pure copper powder is heated to a temperature of 400°C or higher, In the shaping step, the heated pure copper powder is irradiated with infrared laser light to melt and solidify the pure copper powder, thereby forming the metal shaped body. A method for manufacturing a metal shaped body.

3. The method for producing a metal shaped body according to claim 1 or 2, comprising: In the manufacturing process, the heated metal powder is supplied toward a focal point of the emitted laser light, whereby the metal powder is melted and solidified to form a manufacturing layer, and the manufacturing layer is stacked to form the metal manufactured object. A method for manufacturing a metal shaped body.

4. The method for producing a metal shaped body according to claim 3, The preheating step includes a step of heating a carrier gas that carries the metal powder, and a step of heating the metal powder by causing the heated carrier gas to carry the metal powder. A method for manufacturing a metal shaped body.

5. 1. A modeling apparatus, comprising: a preheating unit for preheating metal powder, which is a raw material for the metal shaped body, before the metal powder is melted by the laser light; a laser light source that irradiates the metal powder heated by the preheating unit with laser light to melt and solidify the metal powder to form the metal shaped object, The preheating unit includes a nozzle that injects the metal powder toward a focal point of the laser light, and a magnetic field forming unit that forms an alternating magnetic field that is applied to the metal powder passing through the nozzle. Modeling equipment.

6. The molding apparatus according to claim 5 , The preheating unit heats the pure copper powder as the metal powder so that the temperature of the pure copper powder is 400°C or higher, The laser light source emits infrared laser light as the laser light to melt the pure copper powder. Modeling equipment.

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