CONSTITUTIVE MODELS OF GW103K MAGNESIUM ALLOY UNDER HOT COMPRESSIVE DEFORMATION

Abstract

To understand the hot deformation behavior of GW103K magnesium alloy (Mg-10Gd-3Y), the author conducted numerical constitutive modeling based on literature experimental data from isothermal compression tests under wide ranges of strain rates (0.001-1) s-1 and deformation temperatures (623-773) K. The true stress and strain were acquired from those tests which were used to develop constitutive models based on the modified Johnson-Cook model and modified Zerilli-Armstrong model. The predicted results from the two models were then compared with the data from the experiment. As a result, the experimental and the predicted data exhibit good agreement. Furthermore, the prediction accuracy of the developed models was assessed by calculating the average absolute relative error (AARE) and correlation coefficient (R). From figures, the author finds that the deformation temperatures and strain rates substantially affect the flow stress behavior of GW103K magnesium alloy. In this work, the author established that the two models could depict the flow stress behavior of the alloy at elevated temperatures throughout the entire ranges of strain, strain rate, and temperature.