Method for stepped radial cooling passages in gas turbine blade

Abstract

A new method for providing stepped radial cooling channels for use in investment casting process, particularly for producing gas turbine blades or vanes, is disclosed. The process involves selecting the cores with two different diameters, smaller diameter cores for airfoil channels and larger diameter cores for root channels. The airfoil cores are bended via especial fixture due to angular design of airfoil relative to root of blade. Then the airfoil cores are inserted into the root cores whereas bended segment of airfoil cores are completely located and locked into the root cores without any requirement to glue or cement at their junction or welding the junction. Then the pairs of cores are placed in the injection wax mold having a cavity with a shape complementary to the final casting design and plurality of grooves therein. Each groove of the mold has a depth equal to a radius of certain number of ceramic cores which correspond to cooling channels of casting. Then the wax is injected for temporary positioning of the cores. The wax blade and located cores therein form a pattern for investment casting.

Dependencies are inferred from the claim text.