Abstract: A method of fabricating a truss core sandwich panel of the type including first and second face sheets secured on opposite sides of a corrugated sheet. The first face sheet is welded to one side of the corrugated sheet and the second face sheet is positioned in contact with the other side of the corrugated sheet. A conductive mandrel is positioned between the first face sheet and the corrugated sheet, the height of the mandrel being less than the distance between the first face sheet and the corrugated sheet by a predetermined amount. The first and second face sheets are positioned between opposed welding electrodes, with the mandrel being coplanar with the electrodes. A welding force is applied to the first and second face sheets by means of the electrodes, the force being sufficient to deflect the first face sheet into contact with the mandrel and to bring the mandrel into contact with the corrugated sheet to permit electrical continuity between the electrodes.

Abstract: The present invention relates to a method for diffusion bonding metallic detail parts to form a structural component. This invention presents an efficient low cost method of establishing and maintaining the required intimate surface contact for solid state diffusion bonding. This contact is achieved by configuring the metallic details such that sufficient stability is present to permit applying bonding forces sufficiently great to plastic flow the to-be-joined surfaces into intimate contact. The self-stability of the detail parts eliminates the need for support tooling and the plastic flow to achieve intimate contact eliminates the need for close tolerance preparation of the detail parts. This method is particularly applicable to the fabrication of hollow internally stiffened structural components in which the shell skins are non-parallel; such as turbofan/turbojet engine vanes and blades.

Abstract: The present invention is a lightweight, internally stiffened aerodynamic shell structure with local fittings and a method for fabricating the same. Two typical type structures are the blades and vanes of a turbo fan engine. The invented structure exhibits heretofore unattainable strength and stiffness to weight ratios and a high degree of structural integrity. It is, therefore, particularly advantageous in applications such as the rotating blades in airborne or ground power conversion equipment. It is an aerodynamically shaped structure comprising metallic stiffening material interposed between, and joined to, a pair of relatively thin corresponding metallic face sheets which form the shell skin of the structure. As a function of design requirements, a root fitting, shroud fitting, and tip rib or fitting are solid-state diffusion bonded to the shell structure.