Mixed powder for powder metallurgy, sintered body, and method of manufacturing sintered body

Patent metadata

Field	Value
Publication number	US-10710155-B2
Application number	US-201615739839-A
Country	US
Kind code	B2
Filing date	Sep 16, 2016
Priority date	Sep 18, 2015
Publication date	Jul 14, 2020
Grant date	Jul 14, 2020

Abstract

Provided is a mixed powder for powder metallurgy having a chemical system not using Ni which causes non-uniform metallic microstructure in a sintered body. A mixed powder for powder metallurgy comprises: a partially diffusion alloyed steel powder in which Mo diffusionally adheres to a particle surface of an iron-based powder; a Cu powder; and a graphite powder, wherein the mixed powder for powder metallurgy has a chemical composition containing Mo: 0.2 mass % to 1.5 mass %, Cu: 0.5 mass % to 4.0 mass %, and C: 0.1 mass % to 1.0 mass %, with the balance consisting of Fe and inevitable impurities, and the partially diffusion alloyed steel powder has: a mean particle diameter of 30 μm to 120 μm; a specific surface area of less than 0.10 m2/g; and a circularity of particles with a diameter in a range from 50 μm to 100 μm of 0.65 or less.

First claim

The invention claimed is:

1. A mixed powder for powder metallurgy, comprising:
a partially diffusion alloyed steel powder in which Mo diffusionally adheres to a particle surface of an iron-based powder;
a Cu powder; and
a graphite powder,
wherein the mixed powder for powder metallurgy has a chemical composition containing Mo in an amount of 0.2 mass % to 1.5 mass %, Cu in an amount of 0.5 mass % to 4.0 mass %, and C in an amount of 0.1 mass % to 1.0 mass %, with the balance consisting of Fe and inevitable impurities, and
the partially diffusion alloyed steel powder has: a mean particle diameter of 30 μm to 120 μm; a specific surface area of less than 0.10 m 2 /g; and a circularity of particles thereof with a diameter in a range from 50 μm to 100 μm of 0.65 or less.

2. The mixed powder for powder metallurgy according to claim 1 ,
wherein the Cu powder has a mean particle diameter of 50 μm or less.

3. The mixed powder for powder metallurgy according to claim 1 ,
wherein the iron-based powder is at least one of an as-atomized powder and an atomized iron powder.

4. The mixed powder for powder metallurgy according to claim 2 ,
wherein the iron-based powder is at least one of an as-atomized powder and an atomized iron powder.

5. A sintered body formed by sintering a green compact that comprises the mixed powder for powder metallurgy according to claim 1 .

6. A sintered body formed by sintering a green compact that comprises the mixed powder for powder metallurgy according to claim 2 .

7. A sintered body formed by sintering a green compact that comprises the mixed powder for powder metallurgy according to claim 3 .

8. A sintered body formed by sintering a green compact that comprises the mixed powder for powder metallurgy according to claim 4 .

9. A method of producing a sintered body, comprising
sintering a green compact of a mixed powder for powder metallurgy that includes: a partially diffusion alloyed steel powder in which Mo diffusionally adheres to a particle surface of an iron-based powder; a Cu powder; and a graphite powder,
wherein the mixed powder for powder metallurgy has a chemical composition containing Mo in an amount of 0.2 mass % to 1.5 mass %, Cu in an amount of 0.5 mass % to 4.0 mass %, and C in an amount of 0.1 mass % to 1.0 mass %, with the balance consisting of Fe and inevitable impurities, and
the partially diffusion alloyed steel powder has: a mean particle diameter of 30 μm to 120 μm; a specific surface area of less than 0.10 m 2 /g; and a circularity of particles thereof with a diameter in a range from 50 μm to 100 μm of 0.65 or less.

10. The method of producing a sintered body according to claim 9 ,
wherein the Cu powder has a mean particle diameter of 50 μm or less.

11. The method of producing a sintered body according to claim 9 ,
wherein the iron-based powder is at least one of an as-atomized powder and an atomized iron powder.

12. The method of producing a sintered body according to claim 10 ,
wherein the iron-based powder is at least one of an as-atomized powder and an atomized iron powder.

13. The mixed powder for powder metallurgy according to claim 1 ,
wherein the circularity is 0.52 or more and 0.65 or less.

14. The mixed powder for powder metallurgy according to claim 2 ,
wherein the circularity is 0.52 or more and 0.65 or less.

15. The mixed powder for powder metallurgy according to claim 1 ,
wherein the Cu powder has a mean particle diameter of 30 μm or more.

16. The mixed powder for powder metallurgy according to claim 2 ,
wherein the Cu powder has a mean particle diameter of 30 μm or more.

Assignees

• Jfe Steel Corp

Inventors

• Takashita Takuya
• Kobayashi Akio
• Nakamura Naomichi
• Sato Itsuya

Classifications

• B22F1/12

  Metallic powder containing non-metallic particles (containing lubricating or binding agents or organic material B22F1/10) · CPC title

• B22F1/17

  Metallic particles coated with metal · CPC title

• B22F1/052

  characterised by a mixture of particles of different sizes or by the particle size distribution · CPC title

• B22F1/05

  Metallic powder characterised by the size or surface area of the particles · CPC title

• B22F1/09

  Mixtures of metallic powders · CPC title