US3643728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of casting nickel base alloys using water-soluble calcia cores
Assignee: RTX Corp
•
Filing: 1970-07-08
•
Granted: 1972-02-22
•
Expires: 1990-07-08
Abstract
Abstract A process for producing heat-resistant metal articles from nickel base or cobalt base superalloys having at least one cavity therein comprising fabricating a ceramic core to the configuration of the cavity, the core consisting essentially of at least 50 percent calcia, the balance, if any, being a refractory ceramic material, the whole fired at a density range of 70 to 100 percent of theoretical density, supporting the core in a mold, casting the nickel alloy therearound and dissolving the core with hot water.
Inventors
- 👤 Charles O Hulse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:12
CPC Classifications
B; B22; B22C; B22C9/00; B22C9/10; B22C9/105
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
22 words
The method of claim 1 wherein the ceramic core is at a density range of 70 to 100 percent of theoretical density.
Claim 2
Dependent Claim
17 words
The method of claim 2 wherein the ceramic core contains a refractory ceramic material inert to water.
Claim 3
Dependent Claim
22 words
The method of claim 3 wherein the refractory ceramic material is selected from the group consisting of MgO, ZrO2, CaO-Al2O3 and MgO-Al2O3.
Claim 4
Dependent Claim
17 words
The method of claim 2 wherein the ceramic core contains a refractory ceramic material reactive with water.
Claim 5
Dependent Claim
19 words
The method of claim 5 wherein the refractory material is selected from the group consisting of SrO and BaO.
References Cited (Backward Citations)
US2383812A
Cited
US3407864A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-21 | 1975-08-23 | 1976-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-21 | 1979-08-23 | 1980-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-21 | 1983-08-23 | 1984-02-22 | $7700.00 | Window Closed / Lapsed |