Dynamic Plastic Response of the Mg-Gd-Y Alloy over a Wide Range of Temperatures

Abstract

In this paper, a new phenomenological and empirically based constitutive model was proposed to change the temperature term in the original Johnson-Cook constitutive model. The new model can be used to describe or predict the stress-strain relation of the metals deformed over a wide range of temperatures even though the current temperatures are lower than the reference temperature. Based on the impact compression data obtained by split Hopkins pressure bar (SHPB) apparatus about one hot-extrudedMg-10Gd-2Y-0.5Zr alloy, the material constants in the new model can be experimentally determined using isothermal and adiabatic stress-strain curves at different strain rates and temperatures. Good agreement is obtained between the predicted and the experimental flowcurves for the hot-extrudedMg-10Gd-2Y-0.5Zr alloy at both quasi-static and dynamic loadings under a wide range of temperatures ever though the current temperatures are lower than the reference temperature.