Material Flow Characteristics on the Forward and Backward Solid Extrusion Process

Abstract

FE simulations were carried out to analyze the influence of die geometry and process condition on the material flow. Deformation pattern and its characteristics in a combined forward and backward solid extrusion process were analyzed in terms of forming loads as the primary parameter, volume ratio of backward solid to forward solid and die pressure between tool-workpiece interfaces. Major parameter is the outer diameter ratio (ODR) of backward solid radius to forward solid radius with constant outer diameter of forward solid. Furthermore, extensive simulation works were conducted to investigate the effect of minor design parameters on stable material flow such as punch corner radius. The deformation pattern of material flow in a combined solid extrusion process is also presented. The results from the process simulation predict the flow modes of workpiece material and the die pressure occurring at the contact surface between workpiece and punch. The process of a combined forward and backward solid extrusion was analyzed using a rigid plastic finite element code to get information about the forming load and die pressure distribution, etc.