Deformation behavior of the Mg-7Zn-3Cu-1Ce alloy during hot compression

Abstract

The flow stress behavior of the Mg-7Zn-3Cu-1Ce alloy was studied on a Gleeble-1500 thermal/mechanical simulation test machine under the maximum deformation degree of 50 %, at a strain rate of 0.01 s-1 to 10 s-1 , and temperature of 573 to 673 K. The hot deformation behavior of the tested alloy during the hot compression process was studied. The experimental results showed that the correlation of the flow stress, strain rate and temperature was obvious and the tested alloy was a strain-ratesensitive material. The deformation activation energy (Q = 191 kJ/mol) and the corresponding stress exponent (n = 5.68) were evaluated by linear regression analysis during the hot deformation process. And the flow stress constitutive equation of the Mg-7Zn-3Cu-1Ce alloy was built by introducing the Zener-Hollomon parameter. There was no recrystallization phenomenon in the microstructure of the tested alloy after hot-compression, and dynamic recovery is the main softening mechanism during the high-temperature deformation. The extruded alloy (extrusion at 673 K) shows excellent mechanical properties both at room and at mid-high temperature.