Metal solid production method
Provided is a method for producing a metal solid, the method being capable of easily producing a metal solid. A method for producing a metal solid, the method comprising covering at least a portion of the periphery of a metal powder with a high-melting-point material having a melting point higher than the melting point of the metal powder; and irradiating the metal powder, at least a portion of the periphery of which is covered with the high-melting-point material, with microwaves to heat the metal powder, thereby sintering or melt-solidifying the metal powder.
1. A method for producing a metal solid, the method comprising:
covering at least a portion of a periphery of a metal powder with a high-melting-point material having a melting point higher than the melting point of the metal powder; and
irradiating the metal powder, at least a portion of the periphery of which is covered with the high-melting-point material, with microwaves to heat the metal powder, thereby sintering or melt-solidifying the metal powder,
wherein in the portion of the metal powder covered with the high-melting-point material, the metal powder and the high-melting-point material are in contact with each other, and the high-melting-point material includes a mixture of:
an insulation material that has a lower degree of absorption of the microwaves than the metal powder, and
an absorbent material that absorbs the microwaves in a temperature zone at least a portion of which is lower than a temperature zone in which the metal powder absorbs the microwaves.
2. The method for producing a metal solid according to claim 1 , wherein the covering at least a portion of the periphery of the metal powder with the high-melting-point material, and the sintering or melt-solidifying the metal powder are repeated.
3. The method for producing a metal solid according to claim 2 , wherein laminated metal solids are formed.
4. The method for producing a metal solid according to claim 1 , wherein the high-melting-point material includes from 1 mass % to 70 mass % of the absorbent material.
5. The method for producing a metal solid according to claim 1 , wherein the insulation material includes an oxide.
6. The method for producing a metal solid according to claim 1 , wherein the absorbent material includes a carbon material.
7. The method for producing a metal solid according to claim 1 , wherein the metal powder includes a metal compound.
8. The method for producing a metal solid according to claim 1 , wherein the metal powder further includes an alloy component.
9. The method for producing a metal solid according to claim 1 , wherein the metal powder includes a metal oxide, and the metal powder is reduced in the irradiation of the metal powder with microwaves.
10. The method for producing a metal solid according to claim 1 , wherein the metal powder includes a metal oxide, and the metal powder is sintered in the irradiation of the metal powder with microwaves.
11. The method for producing a metal solid according to claim 1 , wherein the high-melting-point material is in the form of a mold or a container.
12. The method for producing a metal solid according to claim 1 , wherein the metal powder is in the form of a green compact.
13. The method for producing a metal solid according to claim 1 , further comprising applying a pressure to the metal powder before irradiating the metal powder with microwaves.
14. The method for producing a metal solid according to claim 1 , further comprising applying a pressure to the metal powder after irradiating the metal powder with microwaves.
15. The method for producing a metal solid according to claim 1 , wherein the irradiating the metal powder with microwaves is performed in an inert gas atmosphere.
16. The method for producing a metal solid according to claim 1 , wherein the irradiating the metal powder with microwaves is performed in a reducing atmosphere.
17. The method for producing a metal solid according to claim 1 , wherein the metal powder includes a metal oxide, and the method further includes reducing the metal oxide before irradiating the metal powder with microwaves.
18. The method for producing a metal solid according to claim 1 , wherein the covering at least a portion of the periphery of the metal powder with a high-melting-point material having a melting point higher than the melting point of the metal powder includes:
forming a layer of the high-melting-point material;
forming a recess in the layer of the high-melting-point material; and
placing the metal powder in the recess.
19. The method for producing a metal solid according to claim 18 , wherein the forming the recess in the layer of the high-melting-point material includes:
curing a portion of the layer of the high-melting-point material; and
removing an uncured portion of the layer of the high-melting-point material.
20. The method for producing a metal solid according to claim 19 , wherein the curing the portion of the layer of the high-melting-point material includes incorporating a curable material into the portion of the layer of the high-melting-point material.
21. The method for producing a metal solid according to claim 20 , wherein the portion of the layer of the high-melting-point material is impregnated with the curable material.