Effect of Shape Complexity on Ram Pressure and Metal Flow in Aluminum Extrusion

Abstract

Product output and quality are directly affected by metal flow through the extrusion die. The current paper investigates the effect of profile complexity on extrusion pressure, metal flow, and product defects. Cold extrusion experiments were performed on three solid profiles of different complexities. Simulations were carried out for these three shapes using the commercial finite element package DEFORM-3D. After verifying against experimental results, numerical work was extended to six more profiles of varying complexity. It was found that profiles of higher complexity usually result in more inhomogeneous metal flow, require larger extrusion forces, and are more susceptible to product defects. Current complexity definitions need to be improved for consistent ranking of die profiles. Factors such as extrusion ratio and die profile symmetry may also play a significant role in the distortion of metal flow through an extrusion die. These findings can be of direct utility in extrusion die design improvement and reduction of extrusion defects related to metal flow.