Optimization of Process Variables in Warm Extrusion of a Mg–Al–Zn Alloy by Numerical Simulation

Magnesium alloys are extensively used in various fields such as automobile, defense, and aerospace due to their high specific strength and good damping properties. Extrusion is one of the important metal forming processes that is used to process the cast alloy into various useful shapes at high production rates. It is also known to improve the workability and strength of the material. Due to these advantages, interest on the extrusion of magnesium alloys has significantly increased in the recent past. But due to poor formability at room temperature, extrusion of Mg alloys in the warm forming temperature range is an important process in the fabrication of these alloys. Optimization of process variables is critical for the minimization of extrusion load and prevention of defects. In this work, numerical simulations of the extrusion process of a Mg–Al–Zn (AZ31) alloy are carried out to predict the optimum combination of process parameters, namely, extrusion ratio, extrusion speed, and extrusion temperature. Hansel Spittle model was used to define the flow stress curve in the simulation. The effect of the process parameters on extrusion load was studied, and the optimum die angle required to minimize the load required for extrusion was predicted.