Friction Processing Technologies

Abstract

The utilisation of friction as an efficient thermo-mechanical source to both weld and process materials in the solid phase has come a long way since the first patent filing by Bevington in the late 19^th Century. It is fair to say that up until the early Eighties, rotation was the primary motion used to practice friction welding for most applications on a commercial basis, certainly for metals. Work by Searle in the Seventies with orbital motion gathered momentum to permit the welding of non-round parts. This was followed by the development of a dedicated machine to use linear reciprocating motion for joining. From the late Eighties onwards an ‘explosion’ of friction based technologies were conceived and promoted. Such processes include friction taper stud and stitch welding, friction hydro pillar processing, friction extrusion, friction plunge welding, third-body friction welding and not least friction stir welding, which must be regarded as the major step change for the welding of aluminium and its alloys. Sandwiched between motion and process developments came more detailed studies of friction surfacing and friction seam welding, which were both the subject of a patent filing in 1941. The aforementioned processes are reviewed and selected processes discussed more fully. Attention is drawn to the applications, industrial sectors, etc., to which they can be aligned.