Friction welded valve seats

摘要

Method of attaching an insert to a valve seat location of an engine involves forming an engine valve seat location with a circular conical face surface constituted of a light metal; forming an insert with a circular conical bonding surface for mating with the face surface, the bonding surface being constituted of a metal dissimilar to the light metal and having a higher hardness and a higher melting temperature than the light metal of the face surface; aligning the axes of the face surface and bonding surface and gradually rotationally driving the insert into the valve seat with sufficient pressure and for a controlled period of time frictionally melt or plasticize a film of the face surface; and thereafter ceasing the rotational driving while holding the surfaces together with sufficient forging pressure and for a period of time to allow the melted film to recrystallize and create a metallurgical bond between the surfaces.