Constitutive modeling of Mg-9Li-3Al-2Sr-2Y at elevated temperatures

Hot deformation behavior of Mg-9Li-3Al-2Sr-2Y alloy was studied via hot compression tests in the temperature range of 423-573 K with different strain rates ranging from 0.001 to 1.0 s(-1) using the Gleeble (R) 3500 thermal-mechanical simulation testing system at the University of Waterloo. A number of constitutive equation models including the Ludwik, Zener-Hollomon and modified Hensel-Spittel models were used to evaluate the correct material parameters for this alloy and assessed in terms of their ability to accurately predict the constitutive behavior. The analysis of the experimental data by the three constitutive models resulted in an excellent description of the flow curves. The results showed that the Ludwik and Zener-Hollomon models lead to a good agreement between the calculated and measured flow stresses during work softening. Whereas, the modified Hensel-Spittel equation was able to describe the entire deformation process for the deformation temperatures studied. The developed models were then applied to predict the stress strain behavior of this alloy under different thermomechanical behavior paths and showed good accuracy. (C) 2015 Elsevier Ltd. All rights reserved.