Patent attributes
Aspects of the invention are directed to a turbine blade assembly and an associated method of manufacture. The turbine blade assembly can include: (a) a unitary structure having an airfoil and a primary root portion; (b) a separately-formed platform; and (c) a secondary root portion that cooperates with the primary root portion to define a root. The platform can be secured in place between the structure and the secondary root portion. In a preferred embodiment, the structure can be formed by casting, and the secondary root portion can be formed by powder metallurgy. Ideally, the structure is configured so as to avoid large changes in section size or to at least make such changes gradual, particularly in transitioning from the airfoil to the primary root portion. The turbine blade assembly can reduce the propensity for defects to form during the manufacturing process. Thus, higher casting yields can be realized.
