US2904430A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of refractory metals
Assignee: Fansteel Inc
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Filing: 1957-10-14
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Granted: 1959-09-15
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Expires: 1977-10-14
Abstract
No abstract record available.
Inventors
- 👤 Donald F Taylor
- 👤 Robert L Baughman
- 👤 Leonard F Yntema
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:25
CPC Classifications
C; C22; C22B; C22B34/00; C22B34/20; C22B34/24; C22B7/00; C22C; C22C1/00; C22C1/04; C22C1/045; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
92 words
THE METHOD OF PURIFYING TANTALUM POWDER CONTAINING AS AN IMPURITY AN EMBRITTLING QUANTITY OF UP TO ABOUT 2% OF ALUMINUM, WHICH COMPRISES: MIXING WITH THE SAID TANTALUM A THIRD METAL POWDER SELECTED FROM THE CLASS CONSISTING OF COPPER, SILVER AND GOLD; AND HEATING THE METAL POWDER MIX AT A TEMPERATURE OF AT LEAST THE SINTERING TEMPERATURE OF THE TANTALUM, THE AMOUNT OF THE SELECTED THIRD METAL ADDED BEING SUFFICIENT TO REACT AND VOLATILIZE OFF WITH THE EMBRITTLING QUANTITY OF ALUMINUM DURING SINTERING TO RENDER THE SINTERED TANTALUM SUFFICIENTLY DUCTILE TO BE WORKED.
Claim 2
Independent Claim
92 words
THE METHOD OF PURIFYING TANTALUM POWDER CONTAINING AS AN IMPURITY AN EMBRITTLING QUANTITY OF UP TO ABOUT 2% OF ALUMINUM, WHICH COMPRISES: MIXING WITH THE SAID TANTALUM A THIRD METAL POWDER SELECTED FROM THE CLASS CONSISTING OF COPPER, SILVER AND GOLD; AND HEATING THE METAL POWDER MIX AT A TEMPERATURE OF AT LEAST THE SINTERING TEMPERATURE OF THE TANTALUM, THE AMOUNT OF THE SELECTED THIRD METAL ADDED BEING SUFFICIENT TO REACT AND VOLATILIZE OFF WITH THE EMBRITTLING QUANTITY OF ALUMINUM DURING SINTERING TO RENDER THE SINTERED TANTALUM SUFFICIENTLY DUCTILE TO BE WORKED.
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) | 1962-09-14 | 1963-03-16 | 1963-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-09-14 | 1967-03-16 | 1967-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-09-14 | 1971-03-16 | 1971-09-15 | $7700.00 | Window Closed / Lapsed |