Method of manufacturing a hollow blade for a turboshaft engine

摘要

A hollow blade for a turboshaft engine, such as a fan rotor blade of large chord, is manufactured by a method in which primary components including two outer metal sheets and at least one intermediate sheet are hot formed so that the components are curved and twisted to a desired shape, diffusion barriers are formed at selected positions on the intermediate sheet, the shaped components are assembled and located on suitable process tooling, the assembled components are diffusion welded together, the welded assembly is internally pressurized by gas to inflate and superplastically deform selected areas to form a hollow in said assembly, and performing finishing operations on the hollow assembly to obtain the hollow blade.