Patent US4280975A successfully refreshed from Google Patents.
US4280975A
Expired / Lapsed
US
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Method for constructing a turbine shroud
Assignee: General Electric Co
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Filing: 1979-10-12
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Granted: 1981-07-28
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Expires: 1999-10-12
Abstract
Abstract A method for constructing a turbine shroud structure includes providing a metal substrate with a plurality of pegs extending therefrom. A ceramic sealing layer of zirconium oxide with about 20 weight percentage magnesium is applied to the peg-metal substrate structure. Intermediate bonding layers may be applied between the ceramic sealing layer and the peg-metal substrate structure. The ceramic sealing layer is then heat treated to a temperature of 1100° C. to increase the rub wear of the ceramic sealing layer and to reduce the thermal stress therein.
Inventors
- 👤 Charles L. Ammann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:31
CPC Classifications
C; C23; C23C; C23C4/00; C23C4/02; C23C4/18; F; F01; F01D; F01D11/00; F01D11/08; F01D11/12; F01D11/122; F01D11/125; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49316; Y10T428/00; Y10T428/12; Y10T428/1234; Y10T428/12375; Y10T428/24; Y10T428/24149
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
85 words
A method of constructing a turbine shroud structure, comprising the steps of: (a) providing a metal substrate; (b) providing said metal substrate with mechanical matrix bonding means; (c) applying a ceramic sealing layer of zirconium oxide with magnesium oxide to said mechanical matrix bonding means; and then (d) heat treating said ceramic sealing layer to increase the rub wear of said ceramic sealing layer and to develop an ordered pattern of very fine cracks therein which reduce the thermal stress in said ceramic sealing layer.
Claim 2
Independent Claim
85 words
A method of constructing a turbine shroud structure, comprising the steps of: (a) providing a metal substrate; (b) providing said metal substrate with mechanical matrix bonding means; (c) applying a ceramic sealing layer of zirconium oxide with magnesium oxide to said mechanical matrix bonding means; and then (d) heat treating said ceramic sealing layer to increase the rub wear of said ceramic sealing layer and to develop an ordered pattern of very fine cracks therein which reduce the thermal stress in said ceramic sealing layer.
Claim 3
Dependent Claim
25 words
A method in accordance with claim 1 in which said ceramic sealing layer comprises zirconium oxide with about 6 to 25 weight percentage magnesium oxide.
Claim 4
Dependent Claim
23 words
A method in accordance with claim 2 in which said ceramic sealing layer comprises zirconium oxide with about 20 weight percentage magnesium oxide.
Claim 5
Dependent Claim
24 words
A method in accordance with claim 2 in which the heat treatment of step (d) transforms metastable cubic zirconium oxide into monoclinic zirconium oxide.
Claim 6
Dependent Claim
24 words
A method in accordance with claim 2 in which the heat treatment of step (d) transforms metastable cubic zirconium oxide into tetragonal zirconium oxide.
Claim 7
Dependent Claim
18 words
A method in accordance with claim 2 in which step (c) includes plasma spraying said ceramic sealing layer.
Claim 8
Dependent Claim
31 words
A method in accordance with claim 2 in which the heat treatment of step (d) comprises heating said ceramic sealing layer to a temperature of between about 900° to 1400° C.
Claim 9
Dependent Claim
28 words
A method in accordance with claim 2 in which said mechanical matrix bonding means provided in step (b) comprises a plurality of pegs extending from said metal substrate.
Claim 10
Dependent Claim
26 words
A method in accordance with claim 2 in which step (c) includes applying said ceramic sealing layer to a thickness of less than about 0.090 inches.
References Cited (Backward Citations)
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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) | 1984-07-27 | 1985-01-26 | 1985-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-27 | 1989-01-26 | 1989-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-27 | 1993-01-26 | 1993-07-28 | $7700.00 | Window Closed / Lapsed |