Metal founding – Process – Shaping a forming surface
Patent
1975-12-29
1978-06-06
Husar, Francis S.
Metal founding
Process
Shaping a forming surface
106 389, 164 34, 164 41, 164121, 164127, 164138, 164361, 164369, B22C 102, B22C 904, B22C 910, B22C 912
Patent
active
040930173
ABSTRACT:
A porous high-silica core is disclosed for use in directional solidification casting processes having exceptional thermal stability at temperatures above 1650.degree. C. and containing mineralizers which promote the formation of cristobalite. The cores may be made by mixing at least 75 parts of essentially pure fused silica particles with 1 to 25 parts of activating particles containing a mineralizer, such as an alkali metal or alkaline earth metal compound, may be fired at a temperature of 1000.degree. to 1300.degree. C. until they contain 35 percent or more of cristobalite and may then be cooled to room temperature. They may thereafter be incorporated in a shell mold in accordance with the "lost-wax" process and preheated with the shell mold at a temperature of 1300.degree. to 1600.degree. C. to provide a cristobalite content of 60 to 85 percent or more within a short period of time, such as 10 to 30 minutes, and before a molten superalloy is allowed to flow into the mold. The core has exceptionally high thermal stability and may be maintained at a temperature of 1550.degree. to 1600.degree. C. or higher for one hour or more during the directional solidification process without substantial deformation. The high ultimate use temperature of the core makes it possible to produce better castings by carrying out the D.S. process at a temperature 50.degree. to 100.degree. centigrade higher than previously used.
REFERENCES:
patent: 2211133 (1940-08-01), Krosta
patent: 3401738 (1968-09-01), Parille
patent: 3540519 (1970-11-01), Yates
patent: 3542120 (1970-11-01), Piearcey
patent: 3620289 (1971-11-01), Phipps, Jr.
patent: 3643728 (1972-02-01), Hulse
patent: 3700023 (1972-10-01), Giamei et al.
Eppink Donald L.
Loxley Ted A.
Miller, Jr. John J.
Greene Vincent A.
Hampilos Gus T.
Husar Francis S.
Sherwood Refractories Inc.
LandOfFree
Cores for investment casting process does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cores for investment casting process, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cores for investment casting process will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1487399