US3839054A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preform core materials
Assignee: Corning Glass Works
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Filing: 1973-01-08
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Granted: 1974-10-01
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Expires: 1993-01-08
Abstract
Abstract Preform core bodies consisting essentially of silica and alumina and comprising crystal phases of alpha cristobalite, mullite and alpha alumina which are sufficiently refractory and inert for casting with molten nickel and cobalt base superalloys at temperatures in excess of 1,500*C. are described. The core bodies are manufactured through controlled heat treatment of silicaalumina metal mixtures.
Inventors
- 👤 R Forker
- 👤 M Carson
- 👤 R Washington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:47
CPC Classifications
B; B22; B22C; B22C1/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
163 words
A PREFORM CORE BODY CAPABLE OF WITHSTANDING CONTACT WITH MOLTEN NICKEL AND COBALT BASE SUPERALLOYS AT TEMPERATURES IN EXCESS OF 1,500*C. FORMED BY FIRING A GREEN CORE BODY COMPOSED OF ABOUT 2-20% OF ALUMINUM METAL AND 80-98% OF SILICA BY WEIGHT TO A TEMPERATURE IN THE RANGE OF ABOUT 500*-1,200*C. FOR A PERIOD OF TIME SUFFICIENT TO REACT ESSENTIALLY ALL OF THE ALUMINUM METAL PRESENT IN THE BODY WITH SILIC TO FORM ALUMIUNUM OXIDE AND SILICON METAL, COOLING THE BODY AT LEAST TO A TEMPERATURE AT WHICH ALPHA CRISTOBALITE WILL FORM THEREIN, AND FLASH-FIRING THE BODY AT LEAST ONCE AT A TEMPERATURE IN THE RANGE OF ABOUT 1,000*-1,650*C. FOR A TIME IN THE RANGE OF ABOUT 1/412 HOURS, SAID PREFORM CORE BODY BEING COMPOSED OF ABOUT 50-96% SIO2, 4-37% AL2O3, AND NOT MORE THAN 15% SILICON METAL BY WEIGH, AND SAID SIO2 AND AL2O3 BEING PRESENT IN SAID PREFORM CORE BODY IN THE FORM OF ALPHA CRISTOBALITE, ALPHA ALUMINA AND MULLITE CRYSTALLINE PHASES.
Claim 2
Dependent Claim
163 words
A PREFORM CORE BODY CAPABLE OF WITHSTANDING CONTACT WITH MOLTEN NICKEL AND COBALT BASE SUPERALLOYS AT TEMPERATURES IN EXCESS OF 1,500*C. FORMED BY FIRING A GREEN CORE BODY COMPOSED OF ABOUT 2-20% OF ALUMINUM METAL AND 80-98% OF SILICA BY WEIGHT TO A TEMPERATURE IN THE RANGE OF ABOUT 500*-1,200*C. FOR A PERIOD OF TIME SUFFICIENT TO REACT ESSENTIALLY ALL OF THE ALUMINUM METAL PRESENT IN THE BODY WITH SILIC TO FORM ALUMIUNUM OXIDE AND SILICON METAL, COOLING THE BODY AT LEAST TO A TEMPERATURE AT WHICH ALPHA CRISTOBALITE WILL FORM THEREIN, AND FLASH-FIRING THE BODY AT LEAST ONCE AT A TEMPERATURE IN THE RANGE OF ABOUT 1,000*-1,650*C. FOR A TIME IN THE RANGE OF ABOUT 1/412 HOURS, SAID PREFORM CORE BODY BEING COMPOSED OF ABOUT 50-96% SIO2, 4-37% AL2O3, AND NOT MORE THAN 15% SILICON METAL BY WEIGH, AND SAID SIO2 AND AL2O3 BEING PRESENT IN SAID PREFORM CORE BODY IN THE FORM OF ALPHA CRISTOBALITE, ALPHA ALUMINA AND MULLITE CRYSTALLINE PHASES.
Claim 3
Dependent Claim
47 words
A preform core body according to claim 1 wherein the green core body is composed of about 5-15% aluminum metal and 85-95% silica by weight and the preform core body is composed of about 61-71% SiO2, 9-28% Al2O3, and not more than 11% silicon metal by weight.
Claim 4
Dependent Claim
26 words
A preform core body according to claim 2 which contains not less than about 68% SiO2 and not more than about 6% silicon metal by weight.
Claim 5
Dependent Claim
52 words
A preform core body according to claim 2 wherein the green core body contains, in partial substitution for silica, a 96% silica glass in an amount ranging up to about 40% by weight of said green core body, and wherein the preform core body contains up to about 1.5% B2O3 by weight.
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) | 1977-09-30 | 1978-04-01 | 1978-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-30 | 1982-04-01 | 1982-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-30 | 1986-04-01 | 1986-10-01 | $7700.00 | Window Closed / Lapsed |