Patent US3773899A successfully refreshed from Google Patents.
US3773899A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of silicon carbide
Assignee: National Research Development Corp UK
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Filing: 1971-06-14
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Granted: 1973-11-20
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Expires: 1991-06-14
Abstract
Abstract A PROCESS FOR THE PRODUCTION OF SILICON CARBIDE WHISKERS COMPRISING MAINTAINING A SILICON-CONTAINING VAPOUR AND A CARBON-CONTAINING VAPOUR AT A TEMPERATURE OF AT LEAST 1,100*C. IN A REACTION ZONE IN THE PRESENCE OF A SUBSTRATE WHEREBY SILICON CARBIDE WHISKERS ARE DEPOSITED UPON THE SUBSTRATE, AND IS CHARACTERISED BY PROVIDING A SUPER-SATURATED CONCENTRATION OF AN IRON-CONTAINING VAPOUR IN THE REACTION ZONE SO THAT WHISKER GROWTH MAY CONTINUE EVEN WHEN THE SUBSTRATE IS SUBSTANTIALLY ENTIRELY COATED WITH WHISKERS GIVING CONSEQUENT INCREASE IN YIELD AND PROCESS EFFICIENCY.
Inventors
- 👤 T Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:34
CPC Classifications
C; C30; C30B; C30B11/00; C30B11/04; C30B11/08; C30B11/12; C30B25/00; C30B25/005; C30B29/00; C30B29/10; C30B29/36
Claims Analysis
Total Claims: 0
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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) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |