On metal joining and the prediction of the strength of solid-phase joints

The production of some metals, composites and materials by powder and granule metallurgy depends to a great extent on mechanical processes, particularly on joining (the formation of solid-phase joints) the interface between the tool and the metal, al the interfaces between the layers of bimetals or at the interfaces between the particles. The tendency of metallic materials to form solid-phase joints under simultaneous plastic deformation is a basis for pressure welding, plating, powder and granule pressing, and the extrusion of hollow shapes through bridge dies. In conventional metal forming processes joining affects boundary friction and the intensity with which material sticks to the tool, this predetermining the surface quality of the product. (C) 1998 Elsevier Science S.A.