Constitutive behavior and novel characterization of hot deformation of Al-Zn-Mg-Cu aluminum alloy for lightweight traffic

Abstract

Isothermal compression tests of 7A21 aluminum alloy were carried out on a Gleeble-3500 thermal simulator, and the stress-strain curves were obtained at temperatures ranging from 350 to 500 °C and strain rates ranging from 0.01 to 10 s−1. The Arrhenius-type constitutive models with/without strain compensation were established to predict hot deformation mechanical behavior of the alloy based on friction and temperature corrected stress-strain curves, respectively. The model with strain compensation shows a higher prediction accuracy by calculating the average absolute relative error and correlation coefficient. The hot processing maps at different strains were constructed based on the dynamic material model (DMM). The safety strain rates map, a new form of processing map which reflects the variation of critical safety strain rates with the deformation temperatures and true strains, was generated to simplify the acquisition of safety zones throughout the whole deformation process.