Patent US4487799A successfully refreshed from Google Patents.
US4487799A
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Pyrolytic graphite pretreatment for carbon-carbon composites
Assignee: RTX Corp
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Filing: 1984-02-03
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Granted: 1984-12-11
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Expires: 2004-02-03
Abstract
Abstract Carbon-carbon composites are prepared to receive a subsequent protective coating by having a thin layer (1 to 5 mils) of pyrolytic graphite applied to its surface. The graphite layer improves the performance of subsequent protective coatings and is especially useful on carbon-carbon composites having a positive coefficient of thermal expansion.
Inventors
- 👤 Francis S. Galasso
- 👤 Richard D. Veltri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:28
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B35/00; C04B35/71; C04B35/78; C04B35/80; C04B35/83; C04B41/45; C04B41/52; C04B41/80; C04B41/81; C04B41/89; C23; C23C; C23C16/00; C23C16/22; C23C16/26; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/30
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
47 words
A method for preparing a carbon-carbon composite article to receive subsequent protective coating which comprises applying a 1-5 mil layer of pyrolytic graphite to the substrate surface, so that compositional and crystallographic variations in the carbon-carbon article are masked and do not affect the subsequent protective coating.
Claim 2
Independent Claim
47 words
A method for preparing a carbon-carbon composite article to receive subsequent protective coating which comprises applying a 1-5 mil layer of pyrolytic graphite to the substrate surface, so that compositional and crystallographic variations in the carbon-carbon article are masked and do not affect the subsequent protective coating.
Claim 3
Dependent Claim
50 words
In the method of protecting carbon-carbon materials from environmental degradation by diffusing silicon into the surface to produce a SiC based surface layer, the improvement which comprises: applying a 1-5 mil layer of pyrolytic graphite to the surface of the carbon-carbon material prior to diffusing silicon into the article surface.
Claim 4
Dependent Claim
50 words
In the method of protecting carbon-carbon materials from environmental degradation by diffusing silicon into the surface to produce a SiC based surface layer, the improvement which comprises: applying a 1-5 mil layer of pyrolytic graphite to the surface of the carbon-carbon material prior to diffusing silicon into the article surface.
Claim 5
Dependent Claim
30 words
A method as in claim 2 in which the pyrolytic graphite layer is applied by heating the material surface and flowing a mixture of methane and argon over the surface.
Claim 6
Dependent Claim
37 words
A method as in claim 2 in which the SiC layer is produced by embedding the pyrolytic graphite coated material in a pack containing Si, SiC and Al 2 O 3 and heating to an elevated temperature.
References Cited (Backward Citations)
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US4029844A
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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) | 1987-12-11 | 1988-06-11 | 1988-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-11 | 1992-06-11 | 1992-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-11 | 1996-06-11 | 1996-12-11 | $7700.00 | Window Closed / Lapsed |