Sintered friction material for railway vehicles and method for producing the same

Patent metadata

Field	Value
Publication number	US-11674206-B2
Application number	US-201716463878-A
Country	US
Kind code	B2
Filing date	Nov 30, 2017
Priority date	Dec 1, 2016
Publication date	Jun 13, 2023
Grant date	Jun 13, 2023

Abstract

There is provided a sintered friction material for railway vehicles that has excellent frictional properties and wear resistance even in a high speed range of 280 km/hour or more. The sintered friction material for railway vehicles is a green compact sintered material containing, in mass %, Cu: 50.0 to 75.0%, graphite: 5.0 to 15.0%, one or more selected from the group consisting of magnesia, zircon sand, silica, zirconia, mullite, and silicon nitride: 1.5 to 15.0%, one or more selected from the group consisting of W and Mo: 3.0 to 30.0%, and one or more selected from the group consisting of ferrochromium, ferrotungsten, ferromolybdenum, and stainless steel: 2.0 to 20.0%, with the balance being impurities.

First claim

The invention claimed is:

1. A sintered friction material for railway vehicles that is a sintered material of a green compact, the green compact containing in mass %:
Cu, which forms a matrix of the sintered friction material: 50.0 to 75.0%;
graphite: 5.0 to 15.0%;
one or more selected from the group consisting of magnesia, zircon sand, silica, zirconia, mullite, and silicon nitride: 1.5 to 15.0%;
one or more types selected from the group consisting of W particles and Mo particles: 10.0 to 30.0%; and
one or more selected from the group consisting of ferrochromium, ferrotungsten, ferromolybdenum, and stainless steel: 2.0 to 20.0%,
with the balance being impurities.

2. The sintered friction material for railway vehicles according to claim 1 ,
wherein the sintered friction material for railway vehicles is a sintered material formed by causing the green compact to undergo pressure sintering at a temperature ranging from 800 to 1000° C.

3. The sintered friction material for railway vehicles according to claim 2 ,
wherein the green compact further contains one or more selected from the group consisting of
hexagonal boron nitride: 3.0% or less,
molybdenum disulfide: 3.0% or less,
mica: 3.0% or less,
one or more selected from iron sulfide, copper sulfide, and copper matte: 10.0% or less,
vanadium carbide: 5.0% or less, and
Fe: 20.0% or less.

4. The sintered friction material for railway vehicles according to claim 1 ,
wherein the green compact further contains one or more selected from the group consisting of
hexagonal boron nitride: 3.0% or less,
molybdenum disulfide: 3.0% or less,
mica: 3.0% or less,
one or more selected from iron sulfide, copper sulfide, and copper matte: 10.0% or less,
vanadium carbide: 5.0% or less, and
Fe: 20.0% or less.

5. A method for producing the sintered friction material for railway vehicles according to claim 1 , the method comprising:
a forming step of producing the green compact by causing mixed powder to undergo cold forming; and
a pressure sintering step of performing pressure sintering on the green compact at a sintering temperature ranging from 800 to 1000° C. to produce the sintered friction material for railway vehicles.

6. A sintered friction material for railway vehicles that is a sintered material of a green compact, the green compact containing in mass %:
Cu, which forms a matrix of the sintered friction material: 50.0 to 75.0%;
graphite: 5.0 to 15.0%;
one or more selected from the group consisting of magnesia, zircon sand, silica, zirconia, mullite, and silicon nitride: 1.5 to 15.0%;
one or more selected from the group consisting of W and Mo contained in the form of non-ferrous particles: 10.0 to 30.0%; and
one or more selected from the group consisting of ferrochromium, ferrotungsten, ferromolybdenum, and stainless steel: 2.0 to 20.0%,
with the balance being impurities.

Assignees

• Nippon Steel Corp
• Fine Sinter Co Ltd

Inventors

• Kubota Manabu
• Asabe Kazutaka
• Ichikawa Yuki
• Nakano Takeshi
• Okahira Tokitake
• Shimazoe Isao

Classifications

• B22F3/14

  simultaneously · CPC title

• F16D69/027

  Compositions based on metals or inorganic oxides · CPC title

• C22C9/00

  Alloys based on copper · CPC title

• F16D2200/0073

  having lubricating properties · CPC title

• B22F3/02 Primary

  Compacting only · CPC title