Hot deformation behavior and dynamic recrystallization mechanism of Mg-4Al-0.3Mn-1.8Ca-0.4Ce-0.4La alloy

The flow behavior, dynamic recrystallization (DRX) mechanism, and hot workability of Mg-4Al-0.3Mn-1.8Ca-0.4Ce-0.4La (AMX402-0.4Ce-0.4La) alloy were investigated via hot compression experiments. The results show that increasing the deformation temperature and decreasing the strain rate both reduce flow stress. The deformation activation energy at =0.2 is 168.925 kJ/mol, and a strain-compensated constitutive model is established with a correlation coefficient of 99.0%. Furthermore, higher temperatures and lower strain rates promote DRX, although they also lead to the growth of DRXed grains. The particle-stimulated nucleation and discontinuous DRX mechanisms dominant DRX process, while twin-induced DRX and continuous DRX mechanisms assist at low and high temperatures, respectively. In addition, an optimal processing domain of 390-450 °C and 0.001-0.01 s -1 is identified. Compared with AMX402 alloy, the La and Ce additions markedly promotes DRX by modifying the second phase distribution, thereby improving the hot workability.