On the Shearing Process of Ductile Sheet Metals : Material Flow in the Deformation Zone of : the Metal Subjected to Blanking with Tools Having Closed Contours

Abstract

Behavior of metal which lies in the clearance zone and in its neighborhood has been investigated in the case when circular specimens are blanked by tools having circular contours. To the zones of interest, a particular visioplasticity and a strain gauge method are applied. In the circular blanking, materials in the neighboring zones can constrain radial metal flow into and/or out of the clearance zone, so that the flow changes markedly with the proceeding of the punch. The tool clearance affects the flow pattern during the process. It has been found that the time when the ultimate crack initiates depends on the discontinuity of average radial velocities of material across the product and the scrap sides.