Effect of AlLi phase on deformation behavior and dynamic recrystallization of Mg-Li alloy during hot compression

Abstract

Hot deformation behavior of Mg−5Li−3Al−2Zn (LAZ532) alloy with AlLi phase was studied by using isothermal hot compression experiments at the deformation temperature of 473−623 K and the strain rate of 0.001−1 s−1. AlLi phase could significantly increase the peak stress of LAZ532 alloy during hot deformation because of its obstructing effect on the movement of dislocation. A relevant strain-compensated Arrhenius constitutive model was constructed to predict the hot deformation behavior of LAZ532 alloy, and the predicted results were in good agreement with experimental ones. The corresponding hot processing maps were established based on the Murty criterion, and the optimal processing domain was located in the range of 538−623 K and 0.001−0.01 s−1. At the high strain rate, AlLi phase was not beneficial for the flow stability and dynamic recrystallization of LAZ532 alloy during hot compression. In addition, deformation temperature would change the nucleation mechanism of the dynamic recrystallization of LAZ532 alloy.