Patent US3573969A successfully refreshed from Google Patents.
US3573969A
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US
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Method for surface nitriding boron filaments
Assignee: Lockheed Martin Corp
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Filing: 1968-08-19
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Granted: 1971-04-06
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Expires: 1988-08-19
Abstract
Abstract A METHOD FOR SURFACE NITRIDING BORON FILAMENTS TO MAKE THE FILAMENTS USEFUL AS REINFORCEMENT AGENTS IN COMPOSITE MATERIALS. THE METHOD INVOLVES INITIALLY FORMING A LIQUID BORON OXIDE COATING ON THE FILAMENT, FOR EXAMPLE, BY HEATING THE FILAMENT AT TEMPERATURES OF FROM ABOUT 560*C. TO 800*C. IN AN OXIDIZING ATMOSPHERE AND THEN CONVERTING THE LIQUID OXIDE COATING TO A SOLID, CONTINUOUS BORON NITRIDE COATING BY, FOR EXAMPLE, HEATING THE FILAMENT AT TEMPERATURES OF FROM ABOUT 600*C. TO 1100*C. IN A NITROGENCONTAINING ATMOSPHERE.
Inventors
- 👤 Jose Camahort
- 👤 Mario P Gomez
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:49
CPC Classifications
C; C22; C22C; C22C47/00; C22C47/02; C22C47/04; C01; C01B; C01B21/00; C01B21/06; C01B21/064; B; B22; B22F; B22F2998/00; Y; Y10; Y10S; Y10S264/00; Y10S264/19
Claims Analysis
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |