Hard particle, sliding member, and production method of sintered alloy

Patent metadata

Field	Value
Publication number	US-11634799-B2
Application number	US-202117494213-A
Country	US
Kind code	B2
Filing date	Oct 5, 2021
Priority date	Oct 12, 2020
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

Provided is a hard particle in which Cr and W, that are quickly diffused in Mo, are present at the same time as Ni and Mn. Specifically, the hard particle contains Cr: 5% by mass to 20% by mass, W: 2% by mass to 19% by mass, Mo: 25% by mass to 40% by mass, Ni: 10% by mass to 22% by mass, Mn: 10% by mass or less, C: 2.0% by mass or less, Si: 2.0% by mass or less, and a remainder: Fe and unavoidable impurities.

First claim

What is claimed is:

1. A sliding member comprising:
a matrix containing Fe as a main component; and
hard particles dispersed in the matrix,
wherein the hard particles comprise:
Cr: 5% by mass to 20% by mass;
W: 2% by mass to 19% by mass;
Mo: 25% by mass to 40% by mass;
Ni: 10% by mass to 22% by mass;
Mn: 10% by mass or less;
C: 2.0% by mass or less;
Si: 2.0% by mass or less; and
a remainder: Fe and unavoidable impurities.

2. The sliding member according to claim 1 , wherein the matrix contains Cu in an amount of 2% by mass to 12% by mass with respect to 100% by mass of the matrix.

3. The sliding member according to claim 2 , wherein the hard particles further contain La in an amount of 1% by mass to 5% by mass.

4. The sliding member according to claim 1 , wherein:
the matrix contains a second hard particle; and
the second hard particle contains
Mo: 60% by mass to 70% by mass,
Si: 2.0% by mass or less, and
a remainder: Fe and unavoidable impurities.

5. The sliding member according to claim 1 , wherein the sliding member is a valve seat.

6. A production method of making the sliding member according to claim 1 , comprising:
a mixed powder production step of producing mixed powder containing the hard particles and particles for formation of the matrix;
a molded body production step of molding the mixed powder with a mold to obtain a molded body; and
a sintering step of sintering the molded body to obtain the sliding member.

7. The production method according to claim 6 , wherein:
the hard particles are water atomized powder; and
the particles for matrix formation contain flux powder.

8. The sliding member according to claim 1 , wherein the hard particles contain
Cr: 5% by mass to 10% by mass,
W: 3% by mass to 15% by mass,
Mo: 25% by mass to 35% by mass,
Ni: 15% by mass to 20% by mass,
Mn: 6% by mass or less,
C: 1.4% by mass or less,
Si: 1.4% by mass or less, and
the remainder: Fe and the unavoidable impurities.

Assignees

• Toyota Motor Co Ltd
• Fine Sinter Co Ltd

Inventors

• Kamo Yuki
• Yoshida Yusaku
• Inoue Yuta

Classifications

• B22F9/082

  atomising using a fluid (using centrifugal force B22F9/10) · CPC title

• C22C33/0285

  with Cr, Co, or Ni having a minimum content higher than 5% · CPC title

• F16K25/005

  Particular materials for seats or closure elements · CPC title

• F01L2820/01

  Absolute values · CPC title

• B22F2009/0828

  with water · CPC title