Optimisation of magnesium alloy stamping with local heating and cooling using the finite element method

Abstract

A new deep-drawing process with a localised heating and cooling technique was verified to improve sheet forming of a magnesium alloy which is impossible to form by conventional methods at room temperature. Deep-drawing experiments were conducted at a temperature of about 400°C for the blank and deep-drawing tool (holder and die) and at a punch speed of 200mm/min. In the deep-drawing experiment, a drawn-cup of height 90mm (drawing ratio (DR=R0/Rp)=3.6) was achieved using both the local heating and cooling technique and the variable blank holder pressure (BHP) technique. However, the optimal experimental condition of temperature distribution was not estimated for the heating at the flange location and the cooling at the punch shoulder location. The objective of this study is to simply simulate the deep-drawing process with temperature dependency using finite element (FE) simulation and the ANSYS/LS-DYNA FE simulation code to confirm the effective factors. The finite element models were validated against the experimental findings and, subsequently, were used to optimise the temperature distribution in the process in order to produce increased formability.