Hot compression behavior, simulation verification and dynamic recrystallization mechanism of Mg-Gd-Y-Zr alloy

The uniaxial hot compression experiments of Mg-7Gd-3Y-0.5Zr (VW73K) alloy were carried out by using the Instron5982 mechanical testing machine with environmental box. The hot deformation behavior at 350–500 °C and 0.001–1 s−1 was studied. Based on the stress-strain curve obtained from the experiment, a strain-compensated Arrhenius constitutive model, hot processing maps, and dynamic recrystallization (DRX) kinetics model of VW73K alloy were established. The results show that the machinable area of VW73K alloy is 450–500 °C and 0.001–0.1 s−1. Under machinable parameters, the force-displacement data obtained from the experiment are highly consistent with the finite element simulation, verifying the dependability of the strain-compensated Arrhenius constitutive model for the rheological behavior of VW73K alloy during hot compression. VW73K alloy is more easily to DRX at high temperatures and low strain rates, with higher recrystallization volume fraction and faster recrystallization rate. The DRX process of VW73K alloy during hot compression is completed by the collaboration of discontinuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX).