Predicting Effect of Temperature, Strain Rate and Strain Path Changes on Forming Limit of Lightweight Sheet Metal Alloys

Abstract

With the advent of novel hot stamping technologies to produce increasingly complex components, conventional FLDs, which are usually only determined at a constant temperature, strain rate and strain path, are unable to provide an accurate definition of formability. This is particularly the case with the solution Heat treatment, Forming and in-die Quenching (HFQ) process. In this work, a viscoplastic constitutive model was developed to predict the flow stress and formability of a sheet metal alloy undergoing temperature, strain rate and strain path changes. The capability of the proposed model was demonstrated by presenting the effect of these varying conditions on the stress-strain curves and FLDs of the aluminium alloy AA5754.