METHOD AND APPARATUS FOR BIMETALLIC CASTING WITHOUT METALLURGICAL BOND

摘要

Method and apparatus for bimetallic casting in which a shape such as an airfoil which has anisotropic metallurgical properties is bonded to a second shape by casting. A disposable pattern with a configuration desired in the second shape is attached to the first shape and an investment mold is formed about the pattern in the usual investment mold making procedure. A barrier layer is provided at least about those portions of the first shape which are to be bonded to the second shape to prevent interfacial melting or diffusion bonding at the union between the first and second shapes. The pattern material is then removed, leaving an investment casting mold having a casting cavity conforming to the second shape. Molten metal is then poured into the casting cavity and solidifies to form the second shape without any significant metallurgical bonding occurring between the two shapes.