Friction and Lubrication in Sheet Metal Forming

The type of lubrication regime which occurs in a metal forming operation has a strong influence on the frictional conditions as well as on other important factors such as product surface finish and tooling wear rates. The various types of regimes which can occur are reviewed, together with what is known about their incidence in sheet metal forming operations. In the light of this information it can be seen that the commonly used methods of characterizing friction in analytical models of metal forming processes will often lead to erroneous results. Suggestions for improved methods of characterizing friction are made.