Effects of ác+a？ slip mode on microstructure evolution and compressive flow behavior of extruded dilute Mg-0.5Bi-0.5Sn-0.5Mn alloy
(1. School of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China;
2. Salt Lake Chemical Engineering Research Complex, Qinghai University, Xining 810016, China;
3. School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300132, China)
2. Salt Lake Chemical Engineering Research Complex, Qinghai University, Xining 810016, China;
3. School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300132, China)
Abstract: The influence of the slip mode on the microstructure evolution and compressive flow behavior at different strains in an extruded dilute Mg-0.5Bi-0.5Sn-0.5Mn alloy was analyzed through electron backscatter diffraction, X-ray diffraction, transmission electron microscopy, and hot compression tests. The results showed that at a low strain of 0.05, the basal áa？, pyramidal áa？ and ác+a？ slip modes were simultaneously activated. Nevertheless, at the middle stage of deformation (strain of 0.1, 0.2 and 0.5), the áa？ slip mode was difficult to be activated and ác+a？ slip mode became dominant. The deformation process between strains of 0.2 and 0.5 was primarily characterized by the softening effect resulting from the simultaneous occurrence of continuous dynamic recrystallization and discontinuous dynamic recrystallization. Ultimately, at strain of 0.8, a dynamic equilibrium was established, with the flow stress remaining constant due to the interplay between the dynamic softening brought about by discontinuous dynamic recrystallization and the work-hardening effect induced by the activation of the basal áa？ slip mode.
Key words: dilute Mg-Bi-Sn-Mn alloy; slip mode; hot compression; flow behavior; dynamic recrystallization