US3722574A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of making magnesium oxide cores
Assignee: RTX Corp
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Filing: 1971-06-29
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Granted: 1973-03-27
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Expires: 1991-06-29
Abstract
Abstract Magnesium oxide is utilized as a water soluble core for producing hollow superalloy parts by investment casting techniques. The core can be formed by mixing slurries of magnesium oxide and magnesium oxychloride, allowing the mixture to harden and then firing the body to form the corresponding oxide.
Inventors
- 👤 J Anderson
- 👤 J Perron
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:29
CPC Classifications
B; B22; B22C; B22C9/00; B22C9/10; B22C9/105
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
25 words
The method according to claim 1 wherein said slurry contains between about 12 and 30 w/o magnesium chloride and 60 and 80 w/o magnesium oxide.
Claim 2
Independent Claim
125 words
A method of forming a water-soluble core for use in the manufacture of hollow articles in investment casting processes, said core being adapted to be disposed within the casting so that, upon removal, hollow passages remain, said method including the steps of: admixing an aqueous solution of magnesium chloride with magnesium oxide powder to form a slurry; pouring said slurry into a die of the desired shape and allowing said slurry to harden to form a body corresponding to the shape of said dIe; firing said body to oxidize said magnesium chloride and form a solid magnesium oxide core, and coating the core with zirconium oxide having a particle size less than about 100 microns, the coated core being useful in said investment casting process.
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) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |