Study on the hot deformation behavior of a novel multi-element synergistic strengthening Mg-Al-Ca-Mn-Zn-Sn alloy

Abstract

The hot deformation behavior of homogenized Mg-1.4Sn-0.93Zn-0.83Ca-0.67Mn-0.39Al alloy (designated AXMZT-5) was studied with the Gleeble-1500D simulator at the deformation temperatures of 250–400 ℃ and strain rate of 0.01–1 s−1. The constitutive equation and hot processing map that can accurately predict the hot deformation behavior of the studied alloy were successfully established. The results indicated that the hot processing of AXMZT-5 alloy should avoid the low-temperature area (<300 ℃), and the optimum stable deformation areas were 300–350 ℃/0.01–0.1 s−1 and 350–400 ℃/0.01–1 s−1. Detailed microstructural studies indicate that dynamic recrystallization (DRX) was a crucial factor affecting the stable and unstable area of this alloy. The DRX mechanism includes continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX), and the particle stimulated nucleation (PSN) mechanism. In addition, in-grain misorientation axes (IGMA) analysis results show that non-basal slips were activated at all deformation temperatures, and the slip modes were dominated by basal slip and pyramidal slip, supplemented by prismatic slip.