Hot Deformation Behavior of a New Mg-Sn-Zn-Zr Alloy with High Strength and Toughness

The deformation parameters could affect the behaviors of dynamic recrystallization and dynamic precipitation; thus, it was important to explore the appropriate deformation parameters before the hot processing. In this work, the hot compression deformation behavior of Mg-Sn-Zn-Zr (TZK) alloy was first investigated, and then, the appropriate extrusion deformation parameters were selected to obtain better mechanical properties. The experimental results had first reveal that the preferable deformation temperatures and strain rates were 380 to 430 °C and 0.01 to 0.03 s -1 , respectively. The main deformation mechanism was determined to be particle-stimulated nucleation based on stress index (n) calculations. Then, the dynamic recrystallization mechanism of the safety zone was discontinuous dynamic recrystallization, and with increasing strain rates, {10-12} tensile twin occurred. Additionally, due to the fine-grained strength and higher SF of prismatic and pyramidal slips, the elongation and strength of the extruded TZK alloy reached ~ 18.39 % and ~ 237.05 MPa, respectively. This study was expected to provide guidance for the subsequent hot processing of high-strength and high-toughness TZK alloy.