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US4535035A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oxidation resistant slurry coating for carbon-based materials
Assignee: National Aeronautics and Space Administration
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Filing: 1984-01-17
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Granted: 1985-08-13
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Expires: 2004-01-17
Abstract
Abstract An oxidation resistant coating is produced on carbon-base materials, and the same processing step effects an infiltration of the substrate with silicon containing material. The process comprises making a slurry of nickel and silicon powders in a nitrocellulose lacquer, spraying onto the graphite or carbon-carbon substrate, and sintering in vacuum to form a fused coating that wets and covers the surface as well as penetrates into the pores of the substrate. Optimum wetting and infiltration occurs in the range of Ni-60 w/o Si to Ni-90 w/o Si with deposited thicknesses of 25-100 mg/cm 2 . Sintering temperatures of about 1200° C. to about 1400° C. are used, depending on the melting point of the specific coating composition. The sintered coating results in Ni-Si intermetallic phases and SiC, both of which are highly oxidation resistant. The final coating composition can be further controlled by the length of the sintering time.
Inventors
- 👤 James L. Smialek
- 👤 George C. Rybicki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:46
CPC Classifications
C; C23; C23C; C23C24/00; C23C24/08; C23C24/10; C23C24/103; C23C24/106; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/50; C04B41/51; C04B41/5144; C04B41/80; C04B41/81; C04B41/85; C04B41/88
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
102 words
A method of inhibiting the decomposition of a carbon-base material during high temperature exposure to air comprising the steps of preparing a slurry of nickel powders and silicon powders containing about 60 w/o to about 90 w/o silicon in a nitrocellulose lacquer, spraying said slurry onto a surface of the carbon-base material to a thickness between about 25 mg/cm 2 to about 100 mg/cm 2 in an air environment to coat the same, drying the coated carbon-base material in air, and vacuum-sintering the coated carbon-base material at 1200° C. for one hour and then vacuum sintering at 1325° C. for one hour.
Claim 2
Independent Claim
102 words
A method of inhibiting the decomposition of a carbon-base material during high temperature exposure to air comprising the steps of preparing a slurry of nickel powders and silicon powders containing about 60 w/o to about 90 w/o silicon in a nitrocellulose lacquer, spraying said slurry onto a surface of the carbon-base material to a thickness between about 25 mg/cm 2 to about 100 mg/cm 2 in an air environment to coat the same, drying the coated carbon-base material in air, and vacuum-sintering the coated carbon-base material at 1200° C. for one hour and then vacuum sintering at 1325° C. for one hour.
Claim 3
Independent Claim
71 words
A method of coating a carbon-base material comprising the steps of spraying a slurry containing nickel powders and silicon powders onto said carbon-base material in an air environment, placing said slurry covered carbon-base material in a vacuum, and sintering said slurry covered carbon-base material in said vacuum by heating the same to 1200° C. for one hour and then heating said slurry covered carbon-base material to 1325° C. for one hour.
Claim 4
Independent Claim
71 words
A method of coating a carbon-base material comprising the steps of spraying a slurry containing nickel powders and silicon powders onto said carbon-base material in an air environment, placing said slurry covered carbon-base material in a vacuum, and sintering said slurry covered carbon-base material in said vacuum by heating the same to 1200° C. for one hour and then heating said slurry covered carbon-base material to 1325° C. for one hour.
Claim 5
Dependent Claim
23 words
A method as claimed in claim 2 wherein the slurry contains about 60 w/o to about 90 w/o silicon in a nitrocellulose lacquer.
Claim 6
Dependent Claim
31 words
A method as claimed in claim 2 wherein the carbon-base material is covered with the nickel-silicon slurry to a thickness between about 25 mg/cm 2 to about 100 mg/cm 2 .
Claim 7
Dependent Claim
12 words
A carbon-base material coated in accordance with the method of claim 2.
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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) | 1988-08-12 | 1989-02-11 | 1989-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-12 | 1993-02-11 | 1993-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-12 | 1997-02-11 | 1997-08-13 | $7700.00 | Window Closed / Lapsed |