US4784690A
Expired / Lapsed
US
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Low density tungsten alloy article and method for producing same
Assignee: Osram Sylvania Inc
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Filing: 1985-10-11
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Granted: 1988-11-15
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Expires: 2005-10-11
Abstract
Abstract A low density tungsten alloy article is disclosed and the method for producing the article. The method involves compacting a relatively uniform tungsten alloy powder with the tungsten content comprising no greater than about 90% by weight of the alloy and the balance a matrix phase to produce a preformed article which is then sintered in a reducing atmosphere at a temperature below the melting point of the matrix phase for a sufficient time to form a densified article which is mechanically worked to produce the final article.
Inventors
- 👤 James A. Mullendore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:04
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/12; B22F3/14; F; F42; F42B; F42B12/00; F42B12/72; F42B12/74
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
111 words
A method for producing a low density tungsten alloy article, said method comprising: (a) compacting a relatively uniform tungsten alloy powder with the tungsten content comprising no greater than about 90% by weight of said alloy and the balance a matrix phase consisting essentially of iron and nickel in a weight of nickel to iron being from about 4 to 1 to about 1 to 1 to produce a preformed article: (b) sintering said preformed article in a reducing atmosphere at a temperature below the melting point of said matrix phase for a sufficient time to form a densified article; (c) mechanically working said densified article to produce the final article.
Claim 2
Independent Claim
111 words
A method for producing a low density tungsten alloy article, said method comprising: (a) compacting a relatively uniform tungsten alloy powder with the tungsten content comprising no greater than about 90% by weight of said alloy and the balance a matrix phase consisting essentially of iron and nickel in a weight of nickel to iron being from about 4 to 1 to about 1 to 1 to produce a preformed article: (b) sintering said preformed article in a reducing atmosphere at a temperature below the melting point of said matrix phase for a sufficient time to form a densified article; (c) mechanically working said densified article to produce the final article.
Claim 3
Dependent Claim
20 words
A method of claim 1 wherein said tungsten alloy consists essentially of no greater than about 75% by weight tungsten.
Claim 4
Dependent Claim
49 words
A method of claim 2 wherein said tungsten alloy consists essentialy of from about 40% to about 70% by weight tungsten and the balance a matrix phase consisting essentially of a mixture of nickel and iron in a weight ratio of nickel to iron of about 7 to 3.
Claim 5
Dependent Claim
20 words
A method of claim 3 wherein said preformed article is sintered at from about 1200° C. to about 1400° C.
Claim 6
Dependent Claim
55 words
A method of claim 1 wherein after the sintering step, the densified article having a matrix phase consisting essentially of nickel and iron in a weight ratio of nickel to iron of greater than about 1 is heat treated in an inert atmosphere at a sufficient temperature for a sufficient time to remove residual gases.
Claim 7
Dependent Claim
9 words
An article produced by the method of claim 1.
References Cited (Backward Citations)
US2843921A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-15 | 1992-05-16 | 1992-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-15 | 1996-05-16 | 1996-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-15 | 2000-05-16 | 2000-11-15 | $7700.00 | Window Closed / Lapsed |