Abstract: A method is provided for making a four-piece hollow airfoil. Four metal sheets are preformed into initial shapes. The sheets are sealed together into two pairs or sub-assemblies. Internal cavities are formed in one sheet from each pair prior to sealing. Each sub-assembly is subjected to high temperature and pressure in order to diffusion bond the sheets together at selected points. The cavities of each sub-assembly are then subjected to internal pressure in order to inflate and superplastically deform the sub-assemblies. The inflated sub-assemblies are combined to form a single assembly and the cavities are again subjected to internal pressure in order to bond the sub-assemblies together. The assembly is then exposed to hot isostatic pressing, after which, excess material is machined off.

Abstract: A fabricated article, including a portion of non-uniform sectional thickness, is provided through an improved method employing a plurality of cooperating, particularly shaped and sized sheet metal members or member portions which, in an article including a cavity, generally define selected inner and outer surfaces of the article. Also employed is at least one particularly shaped and sized insert member to provide increased sectional thickness in a selected portion. The sheet metal members or member portions and the insert member are assembled at bonding surfaces so that the sheet metal members or member portions retain the insert between them. Thereafter, the assembly is fabricated into the article by solid state diffusion bonding at the bonding surfaces.

Abstract: A fabricated article, including a portion of non-uniform sectional thickness, is provided through an improved method employing a plurality of cooperating, particularly shaped and sized sheet metal members or member portions which, in an article including a cavity, generally define selected inner and outer surfaces of the article. Also employed is at least one particularly shaped and sized insert member to provide increased sectional thickness in a selected portion. The sheet metal members or member portions and the insert member are assembled at bonding surfaces so that the sheet metal members or member portions retain the insert between them. Thereafter, the assembly is fabricated into the article by solid state diffusion bonding at the bonding surfaces.