Patent US4612162A successfully refreshed from Google Patents.
US4612162A
Expired / Lapsed
US
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Method for producing a high density metal article
Assignee: Osram Sylvania Inc
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Filing: 1985-09-11
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Granted: 1986-09-16
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Expires: 2005-09-11
Abstract
Abstract An improvement is disclosed in a method for producing a metal article of high density comprising pressing a metal powder at a sufficient pressure to form a green article and sintering said green article at a sufficient temperature for a sufficient time to form a sintered article, the improvement being pressing the sintered article at a sufficient temperature for a sufficient time at a sufficient pressure of a non-oxidizing atmosphere to produce the final high density article.
Inventors
- 👤 Ricky D. Morgan
- 👤 Vito P. Sylvester
- 👤 Robert L. Ward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:01
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/12; B22F3/14; B22F3/15
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
97 words
In a method for producing a metal article of high density comprising pressing a metal powder at a sufficient pressure to form a green article and sintering said green article at a sufficient temperature for a sufficient time to form a sintered article, the improvement comprising pressing said sintered article at a temperature of at least about 1750° C. for a sufficient time at a pressure of at least about 20,000 psi of a non-oxidizing atmpshere to produce the final high density article, said powder containing at least one of the metal powders of molybdenum and tungsten.
Claim 2
Dependent Claim
97 words
In a method for producing a metal article of high density comprising pressing a metal powder at a sufficient pressure to form a green article and sintering said green article at a sufficient temperature for a sufficient time to form a sintered article, the improvement comprising pressing said sintered article at a temperature of at least about 1750° C. for a sufficient time at a pressure of at least about 20,000 psi of a non-oxidizing atmpshere to produce the final high density article, said powder containing at least one of the metal powders of molybdenum and tungsten.
Claim 3
Dependent Claim
19 words
An improvement of claim 1 wherein said non-oxidizing atmosphere is selected from the group consisting of argon and nitrogen.
Claim 4
Dependent Claim
41 words
An improvement of claim 1 wherein the density of said final article is greater than about 97% of the theoretical density and the grain size of said final article is essentially the same as the grain size of said sintered article.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-09-15 | 1990-03-17 | 1990-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-15 | 1994-03-17 | 1994-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-15 | 1998-03-17 | 1998-09-16 | $7700.00 | Window Closed / Lapsed |