Hot deformation behavior and microstructural evolution of Mg-Zn-Ca-La alloys

The hot deformation behavior and processing characteristics of Mg-3Zn-0.3Ca-0.4La (wt%) alloys were investigated by hot compression deformation. The results suggested that deformation parameters had significant effects on deformation behavior and dynamic recrystallization of the Mg-Zn-Ca-La alloy. The average activation energy of deformation was calculated to be 188.9 kJ/mol. The processing map was constructed and analyzed based on the dynamic material model, and the optimum hot working window of the alloy was determined to be the temperature of 350 degrees C and the strain rates between 0.001 and 0.01 s(-1). Furthermore, the DRX kinetic model of the Mg-3Zn-0.3Ca-0.4La (wt%) alloy was established, which implied that incomplete dynamic recrystallization occurred for the Mg-Zn-Ca-La alloy in the present work. Microstructure analysis indicated that deformation parameters played a critical role on the microstructure optimization. The dynamically recrystallized (DRXed) region fraction and the DRXed grain size were increased with the increase of deformation temperature and decrease of deformation rates.