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US4134777A
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Method for rapid removal of cores made of Y2 O3 from directionally solidified eutectic and superalloy materials
Assignee: General Electric Co
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Filing: 1977-10-06
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Granted: 1979-01-16
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Expires: 1997-10-06
Abstract
Abstract Caustic solutions are employed in an autoclave process to rapidly remove the cores made of Y 2 O 3 from directionally solidified eutectic alloy and superalloy materials.
Inventors
- 👤 Marcus P. Borom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:27
CPC Classifications
B; B22; B22D; B22D29/00; B22D29/001; B22D29/002
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
82 words
A method for removing a core made of yttria ceramic material having a grain morphology which is characteristic of grains which have undergone partial sintering resulting in a network of narrow interconnecting bridges formed by sintering and which connect adjacent grains and particles, comprising the process steps of: (a) placing the casting and the core of yttria ceramic material in an autoclave containing an aqueous leaching solution containing a material which is one selected from the group consisting of NaOH and KOH;
Claim 2
Independent Claim
82 words
A method for removing a core made of yttria ceramic material having a grain morphology which is characteristic of grains which have undergone partial sintering resulting in a network of narrow interconnecting bridges formed by sintering and which connect adjacent grains and particles, comprising the process steps of: (a) placing the casting and the core of yttria ceramic material in an autoclave containing an aqueous leaching solution containing a material which is one selected from the group consisting of NaOH and KOH;
Claim 3
Dependent Claim
59 words
(b) heating the casting, yttria ceramic material and leaching solution to a temperature of at least about 200° C.; (c) dissolving substantially all of the interconnecting network of ceramic material by chemical attack by the leaching solution, and (d) removing at least some of the undissolved ceramic material from the casting by the solution agitated by the chemical reaction.
Claim 4
Dependent Claim
59 words
(b) heating the casting, yttria ceramic material and leaching solution to a temperature of at least about 200° C.; (c) dissolving substantially all of the interconnecting network of ceramic material by chemical attack by the leaching solution, and (d) removing at least some of the undissolved ceramic material from the casting by the solution agitated by the chemical reaction.
Claim 5
Dependent Claim
18 words
The method of claim 1 wherein the temperature in the autoclave is no greater than about 350° C.
Claim 6
Dependent Claim
30 words
The method of claim 1 wherein the composition of the leaching solution is from about 10 percent by weight to about 70 percent by weight hydroxide and the balance water.
Claim 7
Dependent Claim
10 words
The method of claim 3 wherein the hydroxide is NaOH.
Claim 8
Dependent Claim
10 words
The method of claim 3 wherein the hydroxide is KOH.
Claim 9
Dependent Claim
15 words
The method of claim 1 wherein the temperature in the autoclave is about 290° C.
Claim 10
Dependent Claim
10 words
The method of claim 6 wherein the hydroxide is NaOH.
Claim 11
Dependent Claim
10 words
The method of claim 6 wherein the hydroxide is KOH.
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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) | 1982-01-15 | 1982-07-17 | 1983-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-15 | 1986-07-17 | 1987-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-15 | 1990-07-17 | 1991-01-16 | $7700.00 | Window Closed / Lapsed |