Patent ID: 6991022
Filing Date: 2006-01-31
Classification: B22C,B82Y,C04B

Abstract:
1. A method of manufacture of an investment casting mold comprising, mixing one or more fibers selected from the group consisting of organic fiber, ceramic fiber and mixtures thereof with one or more ceramic fillers to form a first dry blend, mixing fiber and ceramic filler to form a second dry blend which is the same or different from the first dry blend, mixing the first dry blend with a first colloidal sol to form prime coat slurry, mixing the second dry blend with a second colloidal sol to form a backup coat slurry wherein the second colloidal silica sol is the same or different from the first colloidal silica sol and wherein the backup coat slurry is the same or different from the prime coat slurry, applying a coating of the prime coat slurry onto an expendable preform to produce a prime coated preform, applying stucco onto the prime coated preform, drying the stuccoed, prime coated preform, applying a coating of the backup coat slurry onto the stuccoed, prime coated preform to produce a backup coated preform, applying stucco onto the backup coated preform to produce a stuccoed, backup coated preform, drying the stuccoed, backup coated preform, removing the expendable preform from the backup 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.