US4655855A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for refining microstructures of prealloyed titanium powder compacted articles
Assignee: United States Department of the Air Force
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Filing: 1985-07-25
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Granted: 1987-04-07
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Expires: 2005-07-25
Abstract
Abstract The microstructure of titanium alloy powder compacts is refined and improved by a method which comprises beta solution heat treating the compact, hydrogenating and then dehydrogenating the compact.
Inventors
- 👤 Lev Levin
- 👤 Russell G. Vogt
- 👤 Daniel Eylon
- 👤 Francis H. Froes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:02
CPC Classifications
C; C22; C22F; C22F1/00; C22F1/16; C22F1/18; C22F1/183
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
98 words
A method for improving the microstructure of a powder compacted article made by powder metallurgy of titanium alloy powder which comprises, in combination, the steps of: a. beta-solution heat treating said article at a temperature approximately equal to the beta-transus temperature of said alloy; b. cooling said article at a rate in excess of air cooling to room temperature; c. hydrogenating said article at a temperature in the approximate range of 50 to 96% of said beta-transus temperature; and d. dehydrogenating said article at a temperature in the approximate range of 50 to 96% of said beta-transus temperature.
Claim 2
Independent Claim
98 words
A method for improving the microstructure of a powder compacted article made by powder metallurgy of titanium alloy powder which comprises, in combination, the steps of: a. beta-solution heat treating said article at a temperature approximately equal to the beta-transus temperature of said alloy; b. cooling said article at a rate in excess of air cooling to room temperature; c. hydrogenating said article at a temperature in the approximate range of 50 to 96% of said beta-transus temperature; and d. dehydrogenating said article at a temperature in the approximate range of 50 to 96% of said beta-transus temperature.
Claim 3
Dependent Claim
34 words
The method of claim 1 wherein said beta-solution heat treatment is carried out at a temperature ranging from about 5% below to about 10% above said beta-transus temperature for about 10 to 240 minutes.
Claim 4
Dependent Claim
34 words
The method of claim 1 wherein said beta-solution heat treatment is carried out at a temperature in the approximate range of 0 to 5% above said beta-transus temperature for about 10 to 240 minutes.
Claim 5
Dependent Claim
27 words
The method of claim 1 wherein said dehydrogenation step comprises cooling said article at a rate in the approximate range of 10° to 200° C. per hour.
Claim 6
Dependent Claim
15 words
The method of claim 4 wherein said cooling rate is about 50° C. per hour.
Claim 7
Dependent Claim
21 words
The method of claim 1 wherein said article is hydrogenated to a hydrogen level of about 0.1 to 2.3 weight percent.
Claim 8
Dependent Claim
23 words
The method of claim 1 wherein said alloy is Ti-6Al-4V and said article is dehydrogenated to a hydrogen level below 0.012 weight percent.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-04-06 | 1990-10-06 | 1991-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-06 | 1994-10-06 | 1995-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-06 | 1998-10-06 | 1999-04-07 | $7700.00 | Window Closed / Lapsed |