Grain growth activation energy of ECAP-processed Mg-Ce alloy: Effect of deformation temperature

In the present work, the grain growth activation energy, Q was evaluated in a Mg-0.3Ce (wt%) alloy after equal-channel angular pressing (ECAP) processing via route Bc for 4 passes at 300 and 350 °C and followed by isochronal annealing at 150, 250, 350, and 450 °C for 2 h. The results demonstrated that Q depends strongly on the deformation processing. The Q value was equal to 111.4 ± 5.7 kJ/mol for the sample ECAP-processed at 300 °C. While the sample ECAP-processed at 350 °C shows the presence of two different Q values depending on the annealing temperature, QI = 26.5 ± 3.4 kJ/mol in the low-temperature range (150–350 °C) and QII = 120.7 kJ/mol in the high-temperature range (350–450 °C). This behaviour was attributed to the resulting deformation microstructure and the occurrence of dynamic grain growth during ECAP processing at 350 °C.
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