US4164424A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alumina core having a high degree of porosity and crushability characteristics
Assignee: General Electric Co
•
Filing: 1977-10-06
•
Granted: 1979-08-14
•
Expires: 1997-10-06
Abstract
Abstract A core for investment casting directionally solidified eutectic and superalloy material consists of alumina which has a porous microstructure in which the grain morphology is characteristic of grains which have undergone vapor phase transport action.
Inventors
- 👤 Frederic J. Klug
- 👤 Wayne D. Pasco
- 👤 Svante Prochazka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:17
CPC Classifications
B; B22; B22D; B22D27/00; B22D27/04; B22D27/045; B22C; B22C9/00; B22C9/02; B22C9/04; B22C9/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
68 words
A fired ceramic article suitable for use as a core in the investment casting of directionally solidified eutectic and superalloy materials consisting essentially of a porous body of ceramic material having a predetermined configuration and a porosity content of greater than about 20 percent by volume; the body having a porous microstructure in which the grain morphology is characteristic of grains which have undergone vapor phase transport action.
Claim 2
Dependent Claim
68 words
A fired ceramic article suitable for use as a core in the investment casting of directionally solidified eutectic and superalloy materials consisting essentially of a porous body of ceramic material having a predetermined configuration and a porosity content of greater than about 20 percent by volume; the body having a porous microstructure in which the grain morphology is characteristic of grains which have undergone vapor phase transport action.
Claim 3
Dependent Claim
14 words
The ceramic article of claim 1 wherein the ceramic article consist essentially of alumina.
Claim 4
Dependent Claim
44 words
The ceramic article of claim 1 wherein the porosity content is greater than 50 percent by volume, and the porosity is continuous throughout the body, and further including a network of narrow connecting bridges of ceramic material interconnecting mutually adjacent particles of ceramic particles.
Claim 5
Dependent Claim
17 words
The ceramic article of claim 3 wherein the ceramic material of the body consists essentially of alumina.
Claim 6
Dependent Claim
21 words
The ceramic article of claim 4 wherein the alumina is doped with from 5 mole percent to 15 mole percent magnesia.
Claim 7
Dependent Claim
21 words
The ceramic article of claim 2 wherein the alumina is doped with from 5 mole percent to 15 mole percent magnesia.
References Cited (Backward Citations)
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US3859427A
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US3643728A
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US3903225A
Cited
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Cited
US4013477A
Cited
US4073662A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-08-13 | 1983-02-12 | 1983-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-08-13 | 1987-02-12 | 1987-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-08-13 | 1991-02-12 | 1991-08-14 | $7700.00 | Window Closed / Lapsed |