On the drawing limit in micro deep drawing

Abstract

Micro deep drawing becomes a more and more industrial relevant process. But due to size effects new challenges are involved in this process compared to macro deep drawing. The size effects cause an increase of friction and thus hinder the material flow. Therefore the limit drawing ratio in micro deep drawing becomes smaller than that in macro forming. The effect of changes concerning friction and flow behavior on drawing limit in micro deep drawing is subject of the presented investigations in this paper. Scaled deep drawing experiments were carried out with five different punch diameters, whereby the tribological size effects were observed: the friction coefficient between workpiece and tools increases if the process dimension decreases.