US4255495A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Corrosion resistant thermal barrier coating
Assignee: National Aeronautics and Space Administration
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Filing: 1979-10-31
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Granted: 1981-03-10
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Expires: 1999-10-31
Abstract
Abstract The object of the invention is to provide a thermal barrier coating system for protecting metal surfaces at high temperature in normally corrosive environments. The thermal barrier coating system includes a metal alloy bond coating, the alloy containing nickel, cobalt, iron, or a combination of these metals. The system further includes a corrosion resistant thermal barrier oxide coating containing at least one alkaline earth silicate. The preferred oxides are calcium silicate, barium silicate, magnesium silicate, or combinations of these silicates.
Inventors
- 👤 Stanley R. Levine
- 👤 Robert A. Miller
- 👤 Philip E. Hodge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:15
CPC Classifications
F; F02; F02C; F02C7/00; F02C7/30; C; C23; C23C; C23C28/00; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12611; Y10T428/12771; Y10T428/12861; Y10T428/12931; Y10T428/12937; Y10T428/12944
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
103 words
A thermal barrier coating system for protecting the surface of a metal substrate in a hot corrosive gas comprising a metal alloy bond coating containing a metal selected from the group consisting of nickel, cobalt, and iron covering said surface of said substrate, and a corrosion-resistant oxide thermal barrier coating containing at least one alkaline earth silicate selected from the group consisting of calcium silicate in the range of 1.8CaO:1SiO 2 to 3CaO:1SiO 2 , magnesium silicate in the range of 1.8MgO:1SiO 2 and 3MgO:1SiO 2 , and calcium silicate in the range of 1.8CaO:1SiO 2 and 3CaO:1SiO 2 covering said bond coating.
Claim 2
Dependent Claim
103 words
A thermal barrier coating system for protecting the surface of a metal substrate in a hot corrosive gas comprising a metal alloy bond coating containing a metal selected from the group consisting of nickel, cobalt, and iron covering said surface of said substrate, and a corrosion-resistant oxide thermal barrier coating containing at least one alkaline earth silicate selected from the group consisting of calcium silicate in the range of 1.8CaO:1SiO 2 to 3CaO:1SiO 2 , magnesium silicate in the range of 1.8MgO:1SiO 2 and 3MgO:1SiO 2 , and calcium silicate in the range of 1.8CaO:1SiO 2 and 3CaO:1SiO 2 covering said bond coating.
Claim 3
Dependent Claim
26 words
A thermal barrier coating system as claimed in claim 1 wherein the substrate is a metal selected from the group consisting of nickel-base and cobalt-base superalloys.
Claim 4
Dependent Claim
32 words
A thermal barrier coating system as claimed in claim 1 wherein the bond coating is an alloy which contains at least one metal selected from the group consisting of chromium and aluminum.
Claim 5
Dependent Claim
26 words
A thermal barrier coating system as claimed in claim 3 wherein the bond coating is an alloy selected from group consisting of NiCrAlY, CoCrAlY, and NiCoCrAlY.
Claim 6
Dependent Claim
26 words
A thermal barrier coating system as claimed in claim 4 wherein the bond coating has a thickness of between about 0.005 centimeters and about 0.025 centimeters.
Claim 7
Dependent Claim
26 words
A thermal barrier coating system as claimed in claim 1 wherein the oxide thermal barrier coating has a thickness between about 0.012 centimeters and 0.120 centimeters.
Claim 8
Dependent Claim
20 words
A thermal barrier coating system as claimed in claim 6 wherein the oxide has a thickness of about 0.038 centimeters.
Claim 9
Dependent Claim
27 words
A thermal barrier coating system as claimed in claim 1 wherein the corrosion-resistant oxide is calcium silicate in the range of 1CaO:1SiO 2 to 3CaO:1SiO 2 .
Claim 10
Dependent Claim
27 words
A thermal barrier coating system as claimed in claim 1 wherein the corrosion-resistant oxide is magnesium silicate in the range between 1MgO:1SiO 2 and 3MgO:1SiO 2 .
Claim 11
Dependent Claim
27 words
A thermal barrier coating system as claimed in claim 1 wherein the corrosion-resistant oxide is barium silicate in the range between 1BaO:1SiO 2 and 3BaO:1SiO 2 .
Claim 12
Dependent Claim
64 words
A thermal barrier coating system for protecting the surface of a metal substrate in a hot corrosive gas comprising a metal alloy bond coating containing a metal selected from the group consisting of nickel, cobalt, and iron covering said surface of said substrate, and a corrosion resistant oxide thermal barrier coating containing a combination of barium, magnesium, and calcium silicates covering said bond coating.
Claim 13
Dependent Claim
64 words
A thermal barrier coating system for protecting the surface of a metal substrate in a hot corrosive gas comprising a metal alloy bond coating containing a metal selected from the group consisting of nickel, cobalt, and iron covering said surface of said substrate, and a corrosion resistant oxide thermal barrier coating containing a combination of barium, magnesium, and calcium silicates covering said bond coating.
Claim 14
Dependent Claim
26 words
A thermal barrier coating system as claimed in claim 1 wherein the corrosion-resistant oxide thermal barrier coating contains up to 50% by weight of free silica.
References Cited (Backward Citations)
US3006782A
Cited
US4095003A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-09 | 1984-09-08 | 1985-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-09 | 1988-09-08 | 1989-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-09 | 1992-09-08 | 1993-03-10 | $7700.00 | Window Closed / Lapsed |