Patent ID: 6814131
Filing Date: 2004-11-09
Classification: B22C,B82Y,C04B

Abstract:
A method of manufacture of an investment casting mold comprising,mixing refractory fiber, glass fiber, and refractory filler to form a first dry blend, mixing refractory fiber, glass fiber, and refractory filler to form a second dry blend which may be the same or different from the first dry blend, mixing the first dry blend with an aqueous colloidal silica sol to form a refractory prime coat slurry, mixing the second dry blend with an aqueous colloidal silica sol to form a refractory back-up coat slurry which may be the same or different from the refractory prime coat slurry, applying a coating of the prime coat slurry onto an expendable pattern of thermoplastic material to produce a prime coated preform, applying a stucco of refractory material onto the prime coated preform, drying the stuccoed, prime coated preform, applying a coating of the refractory back-up coat slurry onto the stuccoed, prime coated preform to produce a refractory back-up coated preform, applying a stucco of refractory material onto the back-up coated preform to produce a stuccoed, back-up coated preform, drying the stuccoed, refractory back-up coated preform, removing the expendable pattern from the refractory back-up coated preform to produce a green shell mold, and heating the green shell mold to a temperature sufficient to produce a fired ceramic shell mold.