Theoretical and Experimental Investigation of the Effect of the Punch Angle on the Backward Extrusion Process

Abstract

The variation of punch angle on the flow metal for the backward extrusion is investigated theoretically and experimentally. Punches with different semi-cone angles varying from 30, 60, 70, 90 ° have been used to study its effect on the pressure required to extrude indirectly for lead. The findings of this experimental study show agreement in trends with the theoretical predictions. From this study it can be concluded that by a little change in the backward reduction in cross- sectional area different types or modes of extrusion process may be obtained and the streamline profile of the punch surface have an important effect in homogeneity of the material flow in the backward direction i.e. that the working pressure decreased when increasing the punch angles, the fact that the redundant strains will be decreased and there will be less restriction on the material flow also due to the complex deformation situation during the backward extrusion and availability of more than one type of velocity field through the process duration, finite element analysis via ANSYS software may be the superior for application.