Sintering lamination molding apparatus

Abstract

To provide a sintering lamination shaping apparatus capable of producing a three dimensional shaped article having improved mechanical properties.SOLUTION: A sintering lamination shaping device (100) has a powder material supply part (10) for supplying metal powder to a shaping part (2) and a reducing material source (26). The reducing atmosphere is generated by supplying a reducing material from a reducing material source (26) to a powder material supply part (10). Then, under a reducing atmosphere, an oxide film of the metal powder is removed by the powder material supply unit (10) before the metal powder is supplied to the shaping unit (2).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sintering layered manufacturing apparatus. [Background technology]

[0002] Sintering additive manufacturing devices, which create three-dimensional objects by irradiating a laser onto metal powder on the modeling stage, have been put into practical use. Sintering additive manufacturing devices are generally called "metal 3D printers."

[0003] A metal 3D printer has a stage installed in a chamber that constitutes the modeling unit, and metal powder supplied from a powder material supply unit to the modeling unit is irradiated with a laser on the stage, thereby forming a sintered layer.The stage is then sequentially lowered to stack the sintered layers, creating a three-dimensional object.

[0004] Patent Document 1 discloses a typical metal 3D printer. The metal 3D printer supplies nitrogen gas to a chamber that constitutes the modeling unit, and in the presence of nitrogen gas, creates a three-dimensional object while preventing oxidation of the metal powder. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-73752 Summary of the Invention [Problem to be solved by the invention]

[0006] The mechanical properties of three-dimensional objects produced by conventional metal 3D printers are often insufficient. Therefore, an object of the present invention is to provide a sintering additive manufacturing device that can produce three-dimensional objects with improved mechanical properties. [Means for solving the problem]

[0007] Under the above technical problems, the present invention provides: A sintering and layered manufacturing apparatus that irradiates a laser onto metal powder supplied onto a stage of a manufacturing unit to form sintered layers, and then stacks the sintered layers to manufacture a three-dimensional object, a powder material supply unit for supplying metal powder to the molding unit; a reducing material source capable of supplying a reducing material to the powder material supply section; The present invention provides a sintering additive manufacturing device, characterized in that a reducing atmosphere is generated by the reducing material by supplying a reducing material from the reducing material source to the powder material supply section, and in this reducing atmosphere, an oxide film on the metal powder is removed in the powder material supply section before the metal powder is supplied to the manufacturing section. [Brief explanation of the drawings]

[0008] [Figure 1] Schematic diagram of the metal 3D printer in the first embodiment [Figure 2] Schematic diagram showing a first example in which the inside of the storage tank is made into a reducing atmosphere by using a reducing material, and the metal powder is forcibly stirred by a stirring member. [Figure 3] Schematic diagram showing a second example of forcibly stirring metal powder in a storage tank using a gaseous reducing material. [Figure 4] FIG. 10 is a schematic diagram showing a third example in which metal powder in a storage tank is stirred by a stirring member and a gaseous reducing material in a reducing atmosphere. [Figure 5] A schematic diagram showing a fourth example in which metal powder in a storage tank is forcibly stirred by a rotating table under a reducing atmosphere. [Figure 6] A schematic diagram showing a fourth example of forced stirring of metal powder in a storage tank using a vibrating plate under a reducing atmosphere. [Figure 7] Schematic diagram of the metal 3D printer in the second embodiment DETAILED DESCRIPTION OF THE INVENTION [Example]

[0009] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. FIG. 1 is a schematic diagram of a sintering additive manufacturing apparatus, i.e., a metal 3D printer, according to a first embodiment. The metal 3D printer 100 of the first embodiment has a chamber 2 that constitutes the manufacturing section and a stage 4 located at the bottom of the chamber 2, with the stage 4 being driven up and down by an elevation mechanism 6. The metal 3D printer 100 also has a laser irradiation source 8. The laser emitted by the laser irradiation source 8 is directed toward the stage 4. Although not shown, a reflector is located between the laser irradiation source 8 and the stage 4, and the angle of this reflector is controlled by a control unit (not shown) according to input data, as in conventional systems. The control unit also controls the elevation of the stage 4.

[0010] The metal 3D printer 100 has a powder material supply unit 10. The powder material supply unit 10 has a storage tank 12 that stores metal powder, and a powder material supply device 14 that supplies the metal powder from the storage tank 12 to the chamber 2. The powder material supply device 14 is controlled according to input data.

[0011] A powder material supply device 14 supplies a controlled amount of metal powder to the chamber (modeling section) 2 through a nozzle 16. The storage tank 12 has a heater (not shown) that preheats the metal powder in the storage tank 12 and maintains the metal powder at an appropriate temperature.

[0012] A roller (not shown) is installed in chamber 2. Metal powder supplied to chamber 2 through nozzle 16 is formed to a uniform thickness by the roller on stage 4. Next, a laser is irradiated onto the metal powder on stage 4 in accordance with input data. This forms a sintered layer. Any excess metal powder is then collected in recovery tank 18. Thereafter, stage 4 is moved downward in sequence, and the above process is repeated repeatedly. This produces a three-dimensional object of the desired shape by stacking sintered layers.

[0013] Preferably, the metal 3D printer 100 has an inert gas source 22 connected to the chamber 2 via a first pipeline 20. By supplying an inert gas such as nitrogen gas or argon gas from the inert gas source 22 to the chamber 2, a three-dimensional object can be produced in an inert gas atmosphere.

[0014] The material supply unit 10 of the metal 3D printer 100 has a reducible material source 26 connected to the material supply unit 10 via a second pipeline 24. The reducible material of the reducible material source 26 may be any one of formic acid, hydrogen gas, and carbon monoxide gas. Alternatively, the reducible material may be composed of two or more materials selected from formic acid, hydrogen gas, and carbon monoxide gas.

[0015] The purpose of supplying the reducing material to the powder material supply unit 10 is as follows: by creating a reducing atmosphere in the powder material supply unit 10, the oxide film on the metal powder is removed before the metal powder is supplied to the chamber 2.

[0016] Regarding the supply of the reducible material from the reducible material source 26 to the powder material supply unit 10, a configuration may be adopted in which the reducible material is supplied to either the storage tank 12 or the powder material supply device 14. As a modified example, a configuration may be adopted in which the reducible material is supplied to both the storage tank 12 and the powder material supply device 14.

[0017] Preferably, the supply of reducible material from the reducible material source 26 to the storage tank 12 occurs during the filling of the storage tank 12 with metal powder. Alternatively, the reducible material may be supplied to the storage tank 12 during the process of filling the storage tank 12 with metal powder, for example. Alternatively, the reducible material may be supplied to the storage tank 12 from time to time after the storage tank 12 has been filled with metal powder.

[0018] Preferably, the supply of reducing material to the powder material supply unit 10 is stopped during the period when the metal powder is being supplied to the chamber 2. This makes it possible to stably control the amount of metal powder supplied to the chamber 2.

[0019] 2 to 6 show, as examples, specific examples of a configuration for supplying a gaseous reducing material to the storage tank 12. In the first example shown in FIG. 2, the storage tank 12 has a stirring member 30. The metal powder Pw contained in the storage tank 12 is forcibly stirred by the stirring member 30 under a reducing atmosphere. By forcibly stirring the metal powder Pw, it is possible to increase the reliability of oxide film removal under a reducing atmosphere.

[0020] 3, the gas discharge end 24a of the second pipe 24 is extended to the bottom of the storage tank 12. The metal powder Pw can be forcibly stirred by the reducing material discharged from the gas discharge end 24a.

[0021] Figure 4 shows a third example of a configuration that combines the first example of Figure 2 and the second example of Figure 3, and in this third example, the metal powder Pw can be forcibly stirred by the stirring action of the stirring member 30 and the stirring action of the gaseous reducing material discharged from the second pipeline 24.

[0022] 5 shows a fourth example in which the storage tank 12 is provided with a rotary table 32 at its bottom. The rotary table 32 can be driven by an electric motor 34 to forcibly stir the metal powder Pw. Preferably, the rotary table 32 has a plurality of fins 36 on its upper surface.

[0023] 5 shows a configuration in which the rotary table 32 rotates about an axis on a horizontal plane. As a modification, the axis 32a of the rotary table 32 may be inclined from the vertical axis, so that the rotary table 32 is disposed at an angle from the horizontal plane.

[0024] 6 shows a fifth example in which a vibrating plate 40 is provided at the bottom of the storage tank 12. The metal powder Pw can be forcibly stirred by vibrating the vibrating plate 40 with a vibration source 42. Although not shown in the figure, the rotary table 32 shown in the fourth example (FIG. 5) may also be vibrated.

[0025] The configuration described in the second example (FIG. 3) may be added to the configurations of the fourth example (FIG. 5), the fifth example (FIG. 6), and a combination thereof. Specifically, a configuration in which the gas discharge end 24a of the third pipe 24 is extended to the bottom of the storage tank 12 may be added to the fourth example (FIG. 5), the fifth example (FIG. 6), and a combination thereof.

[0026] 2 to 6 are configurations in which a gaseous reducing material is supplied to the storage tank 12. Instead of or in addition to this configuration, a configuration in which a gaseous reducing material is supplied to the powder material supply device 14 may be adopted. Specifically, any of the following configurations (1) to (3) may be adopted. (1) A first configuration in which the source of reducible material 26 is connected to the storage tank 12. (2) A second configuration in which the source of reducible material 26 is connected to the powder material supply device 14. (3) A third configuration in which the source of reducible material 26 is connected to the storage tank 12 and the powder material supply device 14.

[0027] 7 is a schematic diagram of a metal 3D printer 200 according to the second embodiment. In explaining the metal 3D printer 200 according to the second embodiment, the same elements as those in the metal 3D printer 100 according to the first embodiment are given the same reference numerals, and their explanation will be omitted. Below, the distinctive features of the metal 3D printer 200 according to the second embodiment will be explained.

[0028] Referring to FIG. 7, the powder material supply unit 10 included in the metal 3D printer 200 has a configuration that supplies metal powder Pw to the chamber 2 through the upper opening 12a of the storage tank 12, and a reducible material is supplied to the storage tank 12 shown in FIG. 7. The metal 3D printer 200 of the second embodiment does not have a nozzle 16 (FIG. 1) for supplying the metal powder Pw to the chamber 2. Instead, in the material supply unit 10 included in the metal 3D printer 200 of the second embodiment, the piston 30 shown in FIG. 7 is raised, thereby supplying the metal powder Pw to the chamber 2 through the upper opening 12a of the storage tank 12. Reference numeral 32 in FIG. 7 denotes an actuator for driving the piston 30. [Explanation of symbols]

[0029] 100 First embodiment of metal 3D printer 2. Chamber (modeling section) 4 Stages 8 Laser irradiation source 10 Material supply section 12 Storage Tank 14 Powder material feeding device 22 Inert gas source 24 2nd pipeline 24a Gas discharge end 26 Reducible Material Sources Pw metal powder 200 Second Example of Metal 3D Printer

Claims

1. A sintering and layered manufacturing apparatus that irradiates a laser onto metal powder supplied onto a stage of a manufacturing unit to form sintered layers, and then stacks the sintered layers to manufacture a three-dimensional object, a powder material supply unit for supplying metal powder to the molding unit; a reducing material source capable of supplying a reducing material to the powder material supply section; A sintering additive manufacturing device characterized in that a reducing atmosphere is generated by the reducing material by supplying a reducing material from the reducing material source to the powder material supply section, and in that reducing atmosphere, an oxide film on the metal powder is removed in the powder material supply section before the metal powder is supplied to the manufacturing section.

2. The sintering layered manufacturing apparatus according to claim 1, the powder material supply unit has a storage tank that stores metal powder, A sintering additive manufacturing apparatus capable of supplying reducible material to the storage tank from the reducible material source.

3. The sintering layered manufacturing apparatus according to claim 2, A sintering and layered manufacturing apparatus, in which the metal powder in the storage tank is forcibly stirred under a reducing atmosphere.

4. The sintering layered manufacturing apparatus according to claim 3, A sintering and layered manufacturing apparatus, wherein the metal powder in the storage tank is forcibly stirred by a gaseous reducing material supplied to the storage tank.

5. The sintering layered manufacturing apparatus according to claim 3, A sintering and layered manufacturing apparatus having a stirring mechanism that stirs the metal powder in the storage tank.

6. The sintering layered manufacturing apparatus according to claim 1, The powder material supply unit a storage tank for containing metal powder; a powder material supplying device that supplies the metal powder in the storage tank to the molding unit through a nozzle; A sintering additive manufacturing apparatus, wherein the reducible material of the reducible material source is supplied to at least one of the storage tank and the powder material supply device.

7. The sintering layered manufacturing apparatus according to claim 6, A sintering additive manufacturing apparatus, wherein the reducible material from the reducible material source is supplied to the material supply device.

8. The sintering layered manufacturing apparatus according to any one of claims 1 to 7, A sintering and layered manufacturing apparatus, wherein the reducible material of the reducible material source is any one of formic acid, hydrogen gas, and carbon monoxide gas, or two or more materials selected from formic acid, hydrogen gas, and carbon monoxide gas.

9. The sintering layered manufacturing apparatus according to claim 8, further comprising an inert gas source connected to the feature; An additive manufacturing apparatus for sintering, wherein an inert gas is supplied to the manufacturing section from the inert gas source.

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