Patent US4671997A successfully refreshed from Google Patents.
US4671997A
Expired / Lapsed
US
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Gas turbine composite parts
Assignee: RTX Corp
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Filing: 1985-04-08
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Granted: 1987-06-09
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Expires: 2005-04-08
Abstract
Abstract Gas turbine engine carbon-carbon composite components having multilayer coatings resulting in components resistant to oxidation at temperatures greater than 2500° F. A first multilayer coating comprises a pack derived silicon carbide coating covered with a chemical vapor deposition layer of silicon nitride. A second multilayer coating comprises a layer of pyrolytic graphite covered with a pack derived silicon carbide coating covered with a chemical vapor deposition layer of silicon nitride. The third multilayer coating comprises a layer of chemical vapor deposition applied silicon carbide covered with a pack derived silicon carbide coating covered with a chemical vapor deposition layer of silicon nitride. Carbon fibers are carbonized or graphitized, formed into woven structures which are stacked in a prepreg with impregnating resin, pyrolyzed and optionally graphitized to form an engine component, and then coated with the above-described layers to achieve an engine component highly resistant to oxidation at elevated temperatures.
Inventors
- 👤 Francis S. Galasso
- 👤 Richard D. Veltri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:37
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/52; C04B41/80; C04B41/81; C04B41/89; F; F01; F01D; F01D5/00; F01D5/12; F01D5/28; F01D5/288; Y; Y02; Y02T; Y02T50/00; Y02T50/60; Y10; Y10S; Y10S428/00; Y10S428/902; Y10T; Y10T428/00; Y10T428/30
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
100 words
In a gas turbine engine environment wherein a carbon-carbon composite is used, said composite having a pack derived silicon carbide coating bonded to the carbon-carbon composite, and a chemical vapor deposition applied layer of silicon nitride on the outer surface of the silicon carbide layer, the silicon nitride layer having a thickness of from about 3 mils to about 30 mils, the improvement comprising the silicon carbide coating having a thickness from about 0.04 mil to about 30 mils and the gas turbine engine component carbon-carbon composite layer being substantially resistant to oxidation at operation temperatures greater than 2500° F.
Claim 2
Dependent Claim
100 words
In a gas turbine engine environment wherein a carbon-carbon composite is used, said composite having a pack derived silicon carbide coating bonded to the carbon-carbon composite, and a chemical vapor deposition applied layer of silicon nitride on the outer surface of the silicon carbide layer, the silicon nitride layer having a thickness of from about 3 mils to about 30 mils, the improvement comprising the silicon carbide coating having a thickness from about 0.04 mil to about 30 mils and the gas turbine engine component carbon-carbon composite layer being substantially resistant to oxidation at operation temperatures greater than 2500° F.
Claim 3
Dependent Claim
130 words
In a gas turbine engine environment wherein a carbon-carbon composite is used, said composite having a layer of pyrolytic graphite bonded to the carbon-carbon composite, the pyrolytic graphite layer having a thickness of from about 1 mil to about 5 mils, a pack derived silicon carbide coating on the outer layer of the pyrolytic graphite layer, and a chemical vapor deposition applied layer of silicon nitride on the outer surface of the silicon carbide layer, the silicon nitride layer having a thickness of from about 3 mils to about 30 mils, the improvement comprising the silicon carbide coating having a thickness from about 0.04 mil to about 30 mils and the gas turbine engine component carbon-carbon composite layer being substantially resistant to oxidation at operation temperatures greater than 2500° F.
Claim 4
Dependent Claim
130 words
In a gas turbine engine environment wherein a carbon-carbon composite is used, said composite having a layer of pyrolytic graphite bonded to the carbon-carbon composite, the pyrolytic graphite layer having a thickness of from about 1 mil to about 5 mils, a pack derived silicon carbide coating on the outer layer of the pyrolytic graphite layer, and a chemical vapor deposition applied layer of silicon nitride on the outer surface of the silicon carbide layer, the silicon nitride layer having a thickness of from about 3 mils to about 30 mils, the improvement comprising the silicon carbide coating having a thickness from about 0.04 mil to about 30 mils and the gas turbine engine component carbon-carbon composite layer being substantially resistant to oxidation at operation temperatures greater than 2500° F.
Claim 5
Dependent Claim
139 words
In a gas turbine engine environment wherein a carbon-carbon composite is used, said composite having a layer of chemical vapor deposition applied silicon carbide bonded to the carbon-carbon composite, the silicon carbide layer having a thickness of from about 0.5 mil to about 5 mils, a pack derived silicon carbide coating on the outer surface of the silicon carbide coating, and a chemical vapor deposition applied layer of silicon nitride on the outer surface of the pack derived silicon carbide coating, the silicon nitride layer having a thickness of from about 3 mils to about 30 mils, the improvement comprising the pack derived silicon carbide coating having a thickness of from about 0.04 mil to about 30 mils and the gas turbine engine component carbon-carbon composite layer being substantially resistant to oxidation at operation temperatures greater than 2500° F.
Claim 6
Dependent Claim
139 words
In a gas turbine engine environment wherein a carbon-carbon composite is used, said composite having a layer of chemical vapor deposition applied silicon carbide bonded to the carbon-carbon composite, the silicon carbide layer having a thickness of from about 0.5 mil to about 5 mils, a pack derived silicon carbide coating on the outer surface of the silicon carbide coating, and a chemical vapor deposition applied layer of silicon nitride on the outer surface of the pack derived silicon carbide coating, the silicon nitride layer having a thickness of from about 3 mils to about 30 mils, the improvement comprising the pack derived silicon carbide coating having a thickness of from about 0.04 mil to about 30 mils and the gas turbine engine component carbon-carbon composite layer being substantially resistant to oxidation at operation temperatures greater than 2500° F.
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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) | 1990-06-08 | 1990-12-08 | 1991-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-08 | 1994-12-08 | 1995-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-08 | 1998-12-08 | 1999-06-09 | $7700.00 | Window Closed / Lapsed |