Abstract: A method and apparatus for removing undesired material from the internal spaces of parts and more particularly, air cooled gas turbine engine blades. The cleaning method employs a series of an immersion in water to saturate at least a portion of the material, an immersion in a liquid which will freeze the water remaining in the material and on the part or blade directly adjacent to the material and a pressure flush to remove the loosened material from the internal spaces.

Abstract: Age-hardenable alloy parts having melting points in excess of 1000.degree. C., in particular high temperature superalloys, characterized by the presence of such structural defects as cast micropores, and/or grain boundary voids or internal microcracks resulting from high temperature service, are improved in mechanical properties by subjecting said parts to hot isostatic pressure in an autoclave at selected elevated solution temperatures in excess of 50% of the absolute melting point of the alloy and superatmospheric pressures sufficient to remove substantially said defects followed by rapidly cooling the parts in situ from the selected temperature while maintaining the parts under superatmospheric pressure in the autoclave.