US4668579A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Interstitially protected oxidation resistant carbon-carbon composite
Assignee: United States, UNITED STATES AIR FORCE, Secretary of
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Filing: 1984-02-01
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Granted: 1987-05-26
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Expires: 2004-02-01
Abstract
Abstract The carbon fiber bundles in a carbon-carbon composite are protected against oxidation by coating the fiber bundles with at least one protective layer consisting of an underlayer portion of boron carbide and an overlayer portion of silicon carbide.
Inventors
- 👤 Thomas E. Strangman
- 👤 Robert J. Keiser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:18
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B35/00; C04B35/622; C04B35/626; C04B35/628; C04B35/62844; C04B35/62857; C04B35/6286; C04B35/62873; C04B35/62884; C04B35/62894; C04B35/62897; C04B35/71; C04B35/78; C04B35/80; C04B35/83; C04B41/45; C04B41/4584; C04B41/52; C04B41/80; C04B41/81; C04B41/89; C04B2235/00; C04B2235/02; C04B2235/50; C04B2235/52; C04B2235/5208; C04B2235/5216; C04B2235/524; C04B2235/5248; C04B2235/65; C04B2235/656; C04B2235/6567; C04B2235/70; C04B2235/96; C04B2235/9669; C04B2235/9684; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/29; Y10T428/2913; Y10T428/2918; Y10T428/292; Y10T428/30
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
62 words
A multidirectional carbon-carbon composite having from one to ten layers of a protective coating deposited on the carbon fiber bundles of said composite, each of said layers consisting of an underlayer portion of boron carbide and an overlayer portion of silicon carbide, wherein the thickness of each portion of said protective coating is in the approximate range of 0.5 to 5 microns.
Claim 2
Dependent Claim
62 words
A multidirectional carbon-carbon composite having from one to ten layers of a protective coating deposited on the carbon fiber bundles of said composite, each of said layers consisting of an underlayer portion of boron carbide and an overlayer portion of silicon carbide, wherein the thickness of each portion of said protective coating is in the approximate range of 0.5 to 5 microns.
Claim 3
Dependent Claim
22 words
The composite of claim 1 further comprising a layer of pyrolytic carbon between said carbon fiber bundles and said protective coating layer.
Claim 4
Dependent Claim
13 words
The composite of claim 1 further comprising carbonaceous material over said protective coating.
Claim 5
Dependent Claim
16 words
The composite of claim 1 wherein the number of layers of said protective coating is one.
Claim 6
Dependent Claim
17 words
A densified composite in accordance with claim 1 further comprising a surface protective layer of silicon carbide.
Claim 7
Independent Claim
68 words
A method for protecting the carbon fiber bundles in a multidirectional carbon-carbon composite against oxidation which comprises coating an assembled composite with from one to ten layers of a protective coating, each layer consisting of an underlayer portion of boron carbide, and an overlayer portion of silicon carbide, wherein the thickness of each portion of said protective coating is in the approximate range of 0.5 to 5.0 microns.
Claim 8
Independent Claim
68 words
A method for protecting the carbon fiber bundles in a multidirectional carbon-carbon composite against oxidation which comprises coating an assembled composite with from one to ten layers of a protective coating, each layer consisting of an underlayer portion of boron carbide, and an overlayer portion of silicon carbide, wherein the thickness of each portion of said protective coating is in the approximate range of 0.5 to 5.0 microns.
Claim 9
Dependent Claim
18 words
The method of claim 6 wherein said protective layer is applied to the fiber bundles in said composite.
Claim 10
Dependent Claim
28 words
The method of claim 6 wherein said protective layer is applied to a consolidated composite having a layer of pyrolytic carbon over the fiber bundles of said composite.
Claim 11
Dependent Claim
11 words
The method of claim 8 wherein said composite is further densified.
Claim 12
Dependent Claim
19 words
The method of claim 9 wherein the resulting densified composite is provided with a surface coating of silicon carbide.
Claim 13
Dependent Claim
45 words
The method of claim 6 wherein said boron carbide underlayer portion is formed by heating a consolidated preform in an atmosphere containing a mixture of a decomposable boron compound having a melting point below about 100° C., and a decomposable hydrocarbon gas, under deposition conditions.
Claim 14
Dependent Claim
45 words
The method of claim 6 wherein said silicon carbide overlayer portion is formed by heating a consolidated preform in an atmosphere containing a mixture of a decomposable silicon compound having a melting point below about 100° C., and a decomposable hydrocarbon gas, under deposition conditions.
Claim 15
Dependent Claim
42 words
The method of claim 10 wherein said surface coating is applied by heating a densified composite in an atmosphere containing mixture of a decomposable silicon compound having a melting point below about 100° C., and a decomposable hydrocarbon gas, under deposition conditions.
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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) | 1990-05-25 | 1990-11-24 | 1991-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-25 | 1994-11-24 | 1995-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-25 | 1998-11-24 | 1999-05-26 | $7700.00 | Window Closed / Lapsed |