A theoretical and experimental study of friction in metal forming by the use of the forward extrusion process

Friction factor is the main characteristic parameter for the definition of frictional conditions in metal forming processes. Modelling the friction forces at the die/workpiece interface has been the topic of a large amount of research for many years. Several tests have been conducted in this respect, among which extrusion process has been used by many researchers. In this research work friction modelling has been studied by the use of the extrusion process and it is shown that the model works very well for cold extrusion of aluminium in dry condition, but it does not model hot extrusion of lubricated steel adequately.