US5312475A
Expired / Lapsed
US
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Sintered material
Assignee: Federal Mogul Coventry Ltd
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Filing: 1991-09-16
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Granted: 1994-05-17
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Expires: 2011-09-16
Abstract
Abstract Sintered materials and a method for their manufacture are described together with products made therefrom, such as piston rings and valve seat inserts for internal combustion engines. The sintered material comprises a porous matrix with a composition lying in the range expressed in wt % of 8 to 12 chromium, 0.5 to 3 molybdenum, up to 1.5 vanadium, 0.2 to 1.5 carbon, other impurities 2 max., up to 1 manganese sulphide, optionally up to 5 molybdenum disulphide, balance iron, the matrix having a uniform dispersion of submicroscopic particles of molybdenum rich carbides which render the material resistant to thermal softening.
Inventors
- 👤 Charles G. Purnell
- 👤 Paritosh Maulik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:34
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/24; C; C22; C22C; C22C33/00; C22C33/02; C22C33/0257; C22C33/0278; C22C33/0285
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
60 words
A sintered ferrous material which has a porous molybdenum/chrominum martensitic matrix formed from a single alloy having a composition expressed in weight percent consisting essentially of 8-12 chromium, 0.5-3 molybdenum, up to 1.5 vanadium, 0.2-1.5 carbon, other impurities 2 max, and the balance iron, the matrix having sub-microscopic molybdenum-rich carbides less than 1 micron in size substantially uniformly distributed therein.
Claim 2
Dependent Claim
60 words
A sintered ferrous material which has a porous molybdenum/chrominum martensitic matrix formed from a single alloy having a composition expressed in weight percent consisting essentially of 8-12 chromium, 0.5-3 molybdenum, up to 1.5 vanadium, 0.2-1.5 carbon, other impurities 2 max, and the balance iron, the matrix having sub-microscopic molybdenum-rich carbides less than 1 micron in size substantially uniformly distributed therein.
Claim 3
Dependent Claim
21 words
A sintered material according to claim 1, wherein the molybdenum content lies in the range from 1.5 to 2.5 wt %.
Claim 4
Dependent Claim
21 words
A sintered material according to claim 1, wherein the chromium content lies in the range from 9 to 11 wt %.
Claim 5
Dependent Claim
20 words
A sintered material according to claim 1, wherein the composition also contains up to 1 wt % of manganese sulphide.
Claim 6
Dependent Claim
19 words
A sintered material according to claim 1, wherein the composition also contains 2 to 6 wt % of copper.
Claim 7
Dependent Claim
21 words
A sintered material according to claim 1, wherein the carbon content lies in the range from 0.2 to 0.6 wt %.
Claim 8
Dependent Claim
21 words
A sintered material according to claim 1, wherein the carbon content lies in the range from 0.6 to 1.5 wt %.
Claim 9
Dependent Claim
15 words
A piston or sealing ring made of a sintered ferrous material according to claim 6.
Claim 10
Dependent Claim
19 words
A valve seat insert for an internal combustion engine made of a sintered ferrous material according to claim 7.
Claim 11
Dependent Claim
72 words
A sintered ferrous material which has a porous molybdenum/chromium martensitic matrix formed from a single alloy having a composition expressed in weight percent consisting essentially of 8-12 chromium, 0.5-3 molybdenum, up to 1.5 vanadium, 0.2-1.5 carbon, other impurities 2 max, and the balance iron, the matrix having sub-microscopic molybdenum rich carbides less than 1 micron in size substantially uniformly distributed therein, the matrix being infiltrated with copper or a copper based alloy.
Claim 12
Dependent Claim
72 words
A sintered ferrous material which has a porous molybdenum/chromium martensitic matrix formed from a single alloy having a composition expressed in weight percent consisting essentially of 8-12 chromium, 0.5-3 molybdenum, up to 1.5 vanadium, 0.2-1.5 carbon, other impurities 2 max, and the balance iron, the matrix having sub-microscopic molybdenum rich carbides less than 1 micron in size substantially uniformly distributed therein, the matrix being infiltrated with copper or a copper based alloy.
Claim 13
Dependent Claim
21 words
A sintered material according to claim 10, wherein the molybdenum content lies in the range from 1.5 to 2.5 wt %.
Claim 14
Dependent Claim
21 words
A sintered material according to claim 10, wherein the chromium content lies in the range from 9 to 11 wt %.
Claim 15
Dependent Claim
20 words
A sintered material according to claim 10, wherein the composition also contains up to 1 wt % of manganese sulphide.
Claim 16
Dependent Claim
21 words
A sintered material according to claim 10, wherein the carbon content lies in the range from 0.6 to 1.5 wt %.
Claim 17
Dependent Claim
19 words
A valve seat insert for an internal combustion engine made of a sintered ferrous material according to claim 14.
Claim 18
Dependent Claim
104 words
A sintered ferrous material which has a porous matrix having a recticular structure of essentially two phases, a first phase formed from an alloy having a composition expressed in weight percent consisting essentially of 8-12 chromium, 0.5-3 molybdenum, up to 1.5 vanadium, 0.2-1.5 carbon, other impurities 2 max, and the balance iron, the first phase having sub-microscopic molybdenum-rich carbides less than 1 micron, in size substantially uniformly distributed therein, and a second phase of pearlite with some residual ferrite regions formed from a relatively pure iron powder with carbon addition, the two phases having transition zones therebetween, the transition zones comprising martensite and bainite.
Claim 19
Dependent Claim
104 words
A sintered ferrous material which has a porous matrix having a recticular structure of essentially two phases, a first phase formed from an alloy having a composition expressed in weight percent consisting essentially of 8-12 chromium, 0.5-3 molybdenum, up to 1.5 vanadium, 0.2-1.5 carbon, other impurities 2 max, and the balance iron, the first phase having sub-microscopic molybdenum-rich carbides less than 1 micron, in size substantially uniformly distributed therein, and a second phase of pearlite with some residual ferrite regions formed from a relatively pure iron powder with carbon addition, the two phases having transition zones therebetween, the transition zones comprising martensite and bainite.
Claim 20
Dependent Claim
25 words
A sintered material according to claim 16, wherein the molybdenum content of the first phase lies in the range from 1.5 to 2.5 wt %.
Claim 21
Dependent Claim
25 words
A sintered material according to claim 16, wherein the chromium content of the first phase lies in the range from 9 to 11 wt %.
Claim 22
Dependent Claim
19 words
A sintered material according to claim 16, wherein the composition contains up to 1 wt % of manganese sulphide.
Claim 23
Dependent Claim
19 words
A sintered material according to claim 16, wherein the composition also contains 2 to 6 wt % of copper.
Claim 24
Dependent Claim
21 words
A sintered material according to claim 16, wherein the carbon content lies in the range from 0.2 to 0.6 wt %.
Claim 25
Dependent Claim
21 words
A sintered material according to claim 16 wherein the carbon content lies in the range from 0.6 to 1.5 wt %.
Claim 26
Dependent Claim
15 words
A piston or sealing ring made of a sintered ferrous material according to claim 21.
Claim 27
Dependent Claim
19 words
A valve seat insert for an internal combustion engine made of a sintered ferrous material according to claim 22.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-05-16 | 1997-11-15 | 1998-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-16 | 2001-11-15 | 2002-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-16 | 2005-11-15 | 2006-05-17 | $7700.00 | Window Closed / Lapsed |