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 apparatus (100) includes a powder material supply part (10) for supplying metal powder to a shaping part (2), a first reducible material source (22) capable of supplying a reducible material to the shaping part (2), and a second reducible material source (26) capable of supplying a reducible material to the powder material supply part (10). A three dimensional shaped article is manufactured under a reducing atmosphere generated by supplying a reducing material from first and second reducing material sources (22, 26) to a shaping part (2) and a powder material supply part (10).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 first reducible material source capable of supplying a reducible material to the shaping portion; a second reducible material source capable of supplying a reducible material to the powder material supply section; The present invention provides a sintering additive manufacturing device that produces a three-dimensional object in a reducing atmosphere generated by supplying reducing material from the first and second reducing material sources to the manufacturing section and the powder material supply 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 [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] The metal 3D printer 100 has first and second reducible material sources 22, 26. The first reducible material source 22 is connected to the chamber 2 via a first pipe 20. By supplying a reducible material from the first reducible material source 22 to the chamber 2, a three-dimensional object is produced in a reducing atmosphere.

[0014] On the other hand, a second reducible material source 26 is connected to the powder material supply unit 10 via a second pipe 24. The second reducible material source 26 can supply the powder material supply unit 10 with a reducible material.

[0015] The reducing material of the first and second reducing material sources 22, 26 may be any one of formic acid, hydrogen gas, and carbon monoxide gas. Alternatively, the reducing material may be composed of two or more materials selected from formic acid, hydrogen gas, and carbon monoxide gas. The first and second reducing material sources 22, 26 may be a common reducing material source or may be separate reducing material sources.

[0016] The purpose of supplying a reducing material to the powder material supply unit 10 and the chamber 2 is as follows: By creating a reducing atmosphere in the powder material supply unit 10 and the chamber 2 that constitutes the modeling unit, a three-dimensional model can be produced using metal powder with the oxide film removed. This improves the mechanical properties of the produced three-dimensional model.

[0017] Regarding the supply of the reducible material from the second 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.

[0018] Preferably, the supply of reducible material from the second reducible material source 26 to the storage tank 12 occurs during the stage of filling the storage tank 12 with metal powder. Alternatively, for example, the reducible material may be supplied to the storage tank 12 during the process of filling the storage tank 12 with metal powder. Alternatively, the reducible material may be supplied to the storage tank 12 from time to time after the storage tank 12 has finished containing the metal powder.

[0019] Preferably, the supply of gaseous reducing material from the second reducible material source 26 to the powder material supply unit 10 is stopped during the period when the metal powder is being supplied to the chamber 2 through the nozzle 16. This allows the amount of metal powder supplied to the chamber 2 through the nozzle 16 to be stably controlled.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] The configurations of the fourth example (FIG. 5) and the fifth example (FIG. 6) may be added with the configuration described in the second example (FIG. 3). Specifically, a configuration in which the gas discharge end 24a of the pipe 24 is extended to the bottom of the storage tank 12 may be added to the configurations of the fourth example (FIG. 5) and the fifth example (FIG. 6).

[0027] 2 to 6 are configured to supply a gaseous reducing material from the second reducing material source 26 to the storage tank 12. Instead of or in addition to this configuration, a configuration may be adopted in which a gaseous reducing material is supplied to the powder material supply device 14. Specifically, any of the following configurations (1) to (3) may be adopted. (1) A first configuration in which a second source of reducible material 26 is connected to the storage tank 12. (2) A second configuration in which a second source of reducible material 26 is connected to the powder material supply device 14. (3) A third configuration in which a second source of reducible material 26 is connected to the storage tank 12 and the powder material supply device 14.

[0028] 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.

[0029] 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 powder 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]

[0030] 100 Example of a metal 3D printer 2. Chamber (modeling section) 4 Stages 8 Laser irradiation source 10 Powder material supply section 12 Storage Tank 14 Powder material feeding device 22 Second source of reducible material (for powder material supply section) 24 2nd pipeline 24a Gas discharge end 26 First source of reducible material (for chamber) 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 first reducible material source capable of supplying a reducible material to the shaping portion; a second reducible material source capable of supplying a reducible material to the powder material supply section; A sintering and layered manufacturing device characterized by producing a three-dimensional object under a reducing atmosphere generated by supplying reducing material from the first and second reducible material sources to the manufacturing section and the powder material supply 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 and layered manufacturing apparatus, in which the metal powder in the storage tank is forcibly stirred under a reducing atmosphere.

3. 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 a reducible material from a reducible material source is supplied to at least one of the storage tank and the powder material supply device.

4. The sintering layered manufacturing apparatus according to claim 1, A sintering additive manufacturing apparatus, wherein the reducible material of the first 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.

5. The sintering layered manufacturing apparatus according to claim 4, A sintering additive manufacturing apparatus, wherein the reducible material of the second 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.

6. The sintering layered manufacturing apparatus according to claim 5, A sintering additive manufacturing apparatus, wherein the first and second reducible material sources are a common reducible material source.

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