Patent US3852099A successfully refreshed from Google Patents.
US3852099A
Expired / Lapsed
US
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Dense silicon carbide ceramic and method of making same
Assignee: General Electric Co
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Filing: 1972-11-27
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Granted: 1974-12-03
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Expires: 1992-11-27
Abstract
Abstract A dense silicon carbide ceramic is disclosed which is composed of a silicon carbide matrix filled with a boron carbide-silicon carbide composition. The silicon carbide ceramic is prepared by performing a porous silicon carbide body, infiltrating the pores of the body with a boron carbide-silicon carbide melt at a sufficient temperature, and directionally cooling the filled body to advance the solidification front through the body 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 03:23
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
75 words
A SILICON CARBIDE CERAMIC BODY COMPRISING A SILICON CARBIDE MATRIC FILLED WITH A COMPOSITION CONSISTING ESSENTIALLY IN WEIGHT PERCENT OF 55-70 PERCENT OF BORON CARBIDE, 30-45 PERCENT OF SILICON CARBIDE AND, BASED ON THE TOTAL WEIGHT OF THEP COMPOSITION, AN AMOUNT UP TO 10 PERCENT BY WEIGHT AND AT LEAST SUFFICIENT O LOWER THE TEMPERATURE OF LIQUID FORMATION OF SAID COMPSITION, OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF SILICON METAL AND ALUMINUM CARBIDE.
Claim 2
Dependent Claim
75 words
A SILICON CARBIDE CERAMIC BODY COMPRISING A SILICON CARBIDE MATRIC FILLED WITH A COMPOSITION CONSISTING ESSENTIALLY IN WEIGHT PERCENT OF 55-70 PERCENT OF BORON CARBIDE, 30-45 PERCENT OF SILICON CARBIDE AND, BASED ON THE TOTAL WEIGHT OF THEP COMPOSITION, AN AMOUNT UP TO 10 PERCENT BY WEIGHT AND AT LEAST SUFFICIENT O LOWER THE TEMPERATURE OF LIQUID FORMATION OF SAID COMPSITION, OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF SILICON METAL AND ALUMINUM CARBIDE.
Claim 3
Dependent Claim
15 words
The body of claim 1, wherein said matrix comprises at least 70 percent by volume.
Claim 4
Independent Claim
138 words
A method of making a dense silicon carbide ceramic comprising the steps of a. preforming a porous silicon carbide body having a density of at least 70 percent, b. placing a composition consisting essentially in weight percent of 55-70 of boron carbide and 30-45 percent of silicon carbide in contact with the preformed porous body, c. firing the body in an inert atmosphere at a sufficient temperature whereby the composition infiltrates the voids of the preformed porous body, and d. directionally cooling the composite body under a thermal gradient extending across the body from the point at which the infiltrating composition is placed in contact with the body to a point remote from the contact point, with the contact point being at a higher temperature than the remote point to form a dense substantially nonporous silicon carbide ceramic.
Claim 5
Independent Claim
138 words
A method of making a dense silicon carbide ceramic comprising the steps of a. preforming a porous silicon carbide body having a density of at least 70 percent, b. placing a composition consisting essentially in weight percent of 55-70 of boron carbide and 30-45 percent of silicon carbide in contact with the preformed porous body, c. firing the body in an inert atmosphere at a sufficient temperature whereby the composition infiltrates the voids of the preformed porous body, and d. directionally cooling the composite body under a thermal gradient extending across the body from the point at which the infiltrating composition is placed in contact with the body to a point remote from the contact point, with the contact point being at a higher temperature than the remote point to form a dense substantially nonporous silicon carbide ceramic.
Claim 6
Dependent Claim
21 words
The method of claim 3, wherein said preformed porous silicon carbide body is prepared by pressing a particulate silicon carbide mixture.
Claim 7
Dependent Claim
16 words
The method of claim 3, wherein said preformed silicon carbide body is prepared by slip casting.
Claim 8
Dependent Claim
26 words
The method of claim 3, wherein said composition consists essentially of 70 percent by weight of boron carbide and 30 percent by weight of silicon carbide.
Claim 9
Dependent Claim
30 words
The method of claim 3, wherein said composition additionally contains up to 10 percent by weight of an additive selected from the group consisting of silicon metal and aluminum carbide.
Claim 10
Dependent Claim
20 words
ThE method of claim 3, wherein said inert atmosphere is argon and the infiltration is performed under a subatmospheric pressure.
Claim 11
Dependent Claim
18 words
The method of claim 3, wherein said thermal gradient is in the range of 5*-50* C. per centimeter.
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) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |