US3853566A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hot pressed silicon carbide
Assignee: General Electric Co
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Filing: 1972-12-21
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Granted: 1974-12-10
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Expires: 1992-12-21
Abstract
Abstract A dense silicon carbide ceramic is disclosed which is prepared by forming a homogeneous dispersion of a submicron powder of silicon carbide and a boron containing additive wherein the amount of boron additive is equivalent to 0.5-3.0 parts by weight of boron per 100 parts of silicon carbide and hot pressing the dispersion at a temperature of about 1,900-2,000* C. and at a pressure of about 5,000-10,000 psi for a sufficient time whereby a dense, substantially nonporous ceramic is formed.
Inventors
- 👤 S Prochazka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:13
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/575
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
86 words
A DENSE HOT PRESSED SILICON CARBIDE CERAMIC BODY CONSISTING ESSENTIALLY OF B-SILICON CARBIDE AND A BORON CONTAINING ADDITIVE SELECTED FROM THE GROUP CONSISTING OF BORON AND BORON CARBIDE WHEREIN THE AMOUNT OF THE BORON ADDITIVE IS EQUIVALENT TO 0.5-3.0 PARTS BY WEIGHT OF BORON PER 100 PARTS OF SILICON CARBIDE, SAID BORON ADDITIVE BEING IN SOLID SOLUTION WITH THE SILICON CARBIDE, THE CERAMIC BEING SUBSTANTIALLY PORE FREE AND HAVING A DENSITY OF AT LEAST 98% OF THE THEORETICAL DENSITY FOR SILICON CARBIDE AND A FINE-GRAINED MICROSTRUCTURE.
Claim 2
Dependent Claim
86 words
A DENSE HOT PRESSED SILICON CARBIDE CERAMIC BODY CONSISTING ESSENTIALLY OF B-SILICON CARBIDE AND A BORON CONTAINING ADDITIVE SELECTED FROM THE GROUP CONSISTING OF BORON AND BORON CARBIDE WHEREIN THE AMOUNT OF THE BORON ADDITIVE IS EQUIVALENT TO 0.5-3.0 PARTS BY WEIGHT OF BORON PER 100 PARTS OF SILICON CARBIDE, SAID BORON ADDITIVE BEING IN SOLID SOLUTION WITH THE SILICON CARBIDE, THE CERAMIC BEING SUBSTANTIALLY PORE FREE AND HAVING A DENSITY OF AT LEAST 98% OF THE THEORETICAL DENSITY FOR SILICON CARBIDE AND A FINE-GRAINED MICROSTRUCTURE.
Claim 3
Dependent Claim
10 words
The ceramic of claim 1, wherein the additive is boron.
Claim 4
Dependent Claim
11 words
The ceramic of claim 1, wherein the additive is boron carbide.
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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) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |