US4128431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composition for making an investment mold for casting and solidification of superalloys therein
Assignee: General Electric Co
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Filing: 1976-09-08
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Granted: 1978-12-05
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Expires: 1996-09-08
Abstract
Abstract A composition for making shell investment molds for the casting and solidification of superalloys therein embodies preparing a primary slurry composition of a mixture of three different flour grain sizes of fused alumina and a silica binder. The flour grain sizes range from approximately 240 mesh to approximately 400 mesh, U.S. Standard or Tyler screen series.
Inventors
- 👤 Paul S. Svec
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:07
CPC Classifications
B; B22; B22C; B22C9/00; Y; Y10; Y10S; Y10S423/00; Y10S423/19
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
139 words
In a primary slurry mixture having a specific gravity of from about 2.36 to about 2.42 and a viscosity of from about 7 to about 10 as measured with a No. 5 Zahn cup for making an investment mold comprising water, a wetting agent, a refractory material in amounts of from about 65% to about 73% and; a binder material comprising an aqueous based colloidal silica solution having a silica content of from 15 percent to 36 percent; the improvement comprising, as said refractory material, a mixture of three different grain sizes of fused alumina having grain sizes within the range of about 240 to about 400 mesh, U.S. Sieve Series; said mixture comprising 70 to 75% by weight of largest grain size, 10 to 20% by weight of medium grain size and the balance of smallest grain size.
Claim 2
Dependent Claim
139 words
In a primary slurry mixture having a specific gravity of from about 2.36 to about 2.42 and a viscosity of from about 7 to about 10 as measured with a No. 5 Zahn cup for making an investment mold comprising water, a wetting agent, a refractory material in amounts of from about 65% to about 73% and; a binder material comprising an aqueous based colloidal silica solution having a silica content of from 15 percent to 36 percent; the improvement comprising, as said refractory material, a mixture of three different grain sizes of fused alumina having grain sizes within the range of about 240 to about 400 mesh, U.S. Sieve Series; said mixture comprising 70 to 75% by weight of largest grain size, 10 to 20% by weight of medium grain size and the balance of smallest grain size.
Claim 3
Dependent Claim
16 words
The mixture of claim 1 wherein the purity of the alumina is greater than 98 percent.
Claim 4
Dependent Claim
14 words
The mixture of claim 2 wherein the alumina is substantially free of iron contamination.
Claim 5
Dependent Claim
22 words
The mixture of claim 1 including from about 8cc to 12cc per 100 pounds of slurry mixture of a non-ionic wetting agent.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-12-04 | 1982-06-05 | 1982-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-04 | 1986-06-05 | 1986-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-04 | 1990-06-05 | 1990-12-05 | $7700.00 | Window Closed / Lapsed |