Effects of dynamic recrystallization mechanisms on texture evolution in Mg-Gd-Y-Zr-Ag alloy during hot compression

Abstract

In this paper, effects of thermal mechanical parameters on the flow behaviors and microstructure evolution of Mg-7.5Gd-1.5Y-0.4Zr-0.5Ag (wt%) alloy were analyzed by the hot compression test combined with electron backscatter diffraction and transmission electron microscopy. Results demonstrate that increasing temperature or decreasing strain rate can effectively improve the dynamic recrystallization (DRX) degree, decrease the flow stress, and weaken the whole texture intensity. Basal<a>and prismatic<a>slip are the dominant deformation mechanisms during hot compression. At a temperature range of 420–470 °C, discontinuous DRX (DDRX) and continuous DRX (CDRX) synergistically affect the texture evolution. DDRX randomizes the grain orientation and has a strong effect on weakening the basal texture. The limited effect of a single grain induced by CDRX on weakening texture intensity can be strengthened with the increasing number of grains at a high strain. At a high strain rate of 0.1 s⁻¹, orientations of new DRX grains induced by compression twins are scattered, and can also weaken the<0001>//CD texture intensity. Therefore, this study provides the basis for further controlling the DRX behavior and texture characteristics for manufacturing large-scale wrought Mg alloys.