US4062679A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Embrittlement-resistant tantalum wire
Assignee: Nrc Inc
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Filing: 1973-03-29
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Granted: 1977-12-13
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Expires: 1993-03-29
Abstract
Abstract Tantalum and tantalum-rich alloys, particularly in wire form, are stabilized against embrittlement by the addition of 50 to 700 parts per million of silicon and optionally with the further addition of 100 to 500 parts per million of carbon.
Inventors
- 👤 Harold G. Marsh
- 👤 James A. Pierret
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:05
CPC Classifications
C; C22; C22C; C22C1/00; C22C1/04; C22C1/045; C22C27/00; C22C27/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
105 words
In a wrought tantalum product of, substantially pure tantalum containing less than 300 parts per million of columbium, less than 200 parts per million of iron, chromium and nickel combined, less than 50 parts per million of tungsten, less than 10 parts per million of molybdenum, less than 30 parts per million of chromium, and less than 20 parts per million of calcium, the improvement which comprises the inclusion of from about 50 to about 700 parts per million of silicon in the composition of said product whereby said product is improved in resistance to embrittlement when exposed to elevated temperatures in an oxygen-containing environment.
Claim 2
Dependent Claim
105 words
In a wrought tantalum product of, substantially pure tantalum containing less than 300 parts per million of columbium, less than 200 parts per million of iron, chromium and nickel combined, less than 50 parts per million of tungsten, less than 10 parts per million of molybdenum, less than 30 parts per million of chromium, and less than 20 parts per million of calcium, the improvement which comprises the inclusion of from about 50 to about 700 parts per million of silicon in the composition of said product whereby said product is improved in resistance to embrittlement when exposed to elevated temperatures in an oxygen-containing environment.
Claim 3
Dependent Claim
24 words
The wrought tantalum product of claim 1 wherein said product contains in addition from about 100 to about 400 parts per million of carbon.
Claim 4
Dependent Claim
23 words
The wrought product of claim 1 wherein said silicon is present in an amount between about 100 to about 300 parts per million.
Claim 5
Dependent Claim
76 words
A tantalum wire composed of substantially pure tantalum containing less than 300 parts per million of columbium, less than 200 parts per million of iron, chromium and nickel combined, less than 50 parts per million of tungsten, less than 10 parts per million of moybdenum, less than 30 parts per million of chromium, and less than 20 parts per million of calcium, said metal containing from about 50 to about 700 parts per million of silicon.
Claim 6
Dependent Claim
76 words
A tantalum wire composed of substantially pure tantalum containing less than 300 parts per million of columbium, less than 200 parts per million of iron, chromium and nickel combined, less than 50 parts per million of tungsten, less than 10 parts per million of moybdenum, less than 30 parts per million of chromium, and less than 20 parts per million of calcium, said metal containing from about 50 to about 700 parts per million of silicon.
Claim 7
Dependent Claim
21 words
The tantalum wire of claim 4 wherein said metal contains from about 100 to about 300 parts per million of silicon.
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) | 1980-12-12 | 1981-06-13 | 1981-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-12 | 1985-06-13 | 1985-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-12 | 1989-06-13 | 1989-12-13 | $7700.00 | Window Closed / Lapsed |