High temperature deformation behavior of Mg-Gd-Y-Zr alloy with preset twins and the effect of twins on dynamic recrystallization

The Mg-5Gd-3Y-0.5Zr alloy, after solution treatment, was subjected to three-dimensional compression at room temperature and subsequently annealed to preset twins. The effect of preset twins on the high-temperature deformation ability and dynamic recrystallization (DRX) behavior of Mg-5Gd-3Y-0.5Zr alloy was investigated by hot compression of 35 %/0.002 s(-1) at 400 degrees C. The results indicated that pre-twinning provides nucleation sites for dynamic recrystallization, accelerating the occurrence of dynamic recrystallization phenomenon in Mg-5Gd-3Y-0.5Zr alloy. The DRX occurs both continuously and discontinuously around grain boundaries, and twin-induced dynamic recrystallization also propagates along twin boundaries. As the recrystallization progresses, the number of small recrystallized grains increases, while the proportion of original large grains and twins decreases, thus enhancing the strength of the alloy. Additionally, the presence of twins can also enhance the local hardening capability of the alloy during deformation.