Finite Element Optimization of Deep Drawing Process Forming Parameters for Magnesium Alloys

Formability of Magnesium alloys is limited especially at room temperature due to their hexagonal close packed (HCP) structure. At room temperature (RT), the critical resolved shear stress for non basal slip systems is much greater than those for basal slips. As only basal systems may contribute to plastic deformation, magnesium alloys have limited formability at RT. However, increased formability is observed at higher temperatures ranging between 150°C and 300°C due to the activation of additional slip planes. Additionally it has been observed that the formability is very sensitive to strain rates. In this paper, experimental and Finite Element (FE) analysis are applied to develop a methodology to determine the forming limits of magnesium alloys AZ31 and WE43 in the deep drawing process using a ductile fracture criterion based on the strain energy density. Based on the developed methodology optimal forming parameters, namely punch radius, temperature, profile radius and forming depth are determined.