# US 4,391,641 A · Sintered powder metal friction material

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- Number: US 4,391,641 A
- Document ID: US4391641A
- Status: Granted
- Kind: A
- Application number: 06/318,719
- Filed: 1981-11-06
- Granted: 1983-07-05
- Earliest claimed: 1980-12-19
- Assignees: Abex Corporation
- Inventors: Herbert W. Lloyd
- Web page: https://patentgrep.com/patent/US4391641A

## CPC

- F16D 69/027: {Compositions based on metals or inorganic oxides}
- B29C 43/006: {Pressing and sintering powders, granules or fibres}
- F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)

## Abstract

An iron-base, sintered powder metal friction material suitable for railroad braking is disclosed. The friction material comprises, by volume, 10-70% carbon; 0-2.5% sulfur; 0-10% alumina; 1-45% of a metal powder additive selected from the group consisting of copper, manganese, ferrochrome, chrome carbide compounds and mixtures thereof; and the balance iron. In preferred embodiments, the powder metal additives are 11-25% copper, or 9-15% manganese, or 5-20% ferrochrome.

## Claims

### Claim 1

An iron-base, sintered powder metal friction material for railroad braking use formed by solid phase sintering and consisting essentially of, by volume, 10-70% carbon in the form of coke or graphite; 0-2.5% sulfur; 0-10% alumina; 9-40% of a metal powder additive selected from the group consisting of copper, manganese, ferrochrome, and chrome carbide compounds; and the balance iron.

### Claim 2 (depends on 1)

The iron-base, sintered powder metal friction material of claim 1, wherein the metal powder additive is ferrochrome.

### Claim 3 (depends on 1)

The iron-base, sintered powder metal friction material of claim 1, wherein the powder metal additive is a chrome carbide compound.

### Claim 4 (depends on 1)

The iron-base, sintered powder metal friction material of claim 1, which has 3-10% alumina and as the powder metal additive, 9-25% manganese.

### Claim 5 (depends on 1)

The iron-base, sintered powder metal friction material of claim 1, which has 3-10% alumina and, as the powder metal additive, 9-35% copper.

### Claim 6

An iron-base, sintered powder metal friction material for railroad braking use formed by solid phase sintering and consisting essentially of, by volume, 30-40% graphite; 0-2.5% sulfur; 2-8% aluminum oxide; 9-15% manganese, and balance iron.

### Claim 7

An iron-base, sintered powder metal friction material for railroad braking use formed by solid phase sintering and consisting essentially of, by volume, 15-30% graphite; 0-2.5% sulfur; 5-10% aluminum oxide; 4-25% copper, and balance iron.

### Claim 8

An iron-base, sintered powder metal friction material for railroad braking use formed by solid phase sintering and consisting essentially of, by volume, 20-70% carbon in the form of coke or graphite; 0-2.5% sulfur; 1-20% ferrochrome, and balance iron.

### Claim 9 (depends on 8)

The iron-base, sintered powder metal friction material of claim 8, which has 5-20% ferrochrome, 25-45% carbon in the form of graphite and no sulfur.

### Claim 10

An iron-base, sintered powder metal friction material for railroad braking use formed by solid phase sintering and consisting essentially of, by volume, 30-50% carbon in the form of coke or graphite, 10-20% ferrochrome, and balance iron.