Galling phenomena in metal forming

Galling phenomena in metal forming not only affect the quality of the engineered surfaces but also the success or failure of the manufacturing operation itself. This paper reviews the different galling conditions in sheet and bulk metal forming processes along with their evolution and the effects of temperature on galling. A group of anti-galling methods employed to prevent galling defects are also presented in detail. The techniques for quantitatively measuring galling are introduced, and the related prediction models, including friction, wear, and galling growth models, are presented to better understand the underlying phenomena. Galling phenomena in other processes similar to those occurring in metal forming are also examined to suggest different ways of further studying galling in metal forming. Finally, future research directions for the study of galling in metal forming are suggested.