Effect of Sm on dynamic recrystallization of Mg-8Gd-0.5Zr alloy during hot compression

Abstract

Mg-8Gd-0.5Zr (wt%) alloy and Mg-8Gd-3Sm-0.5Zr (wt%) alloy were prepared by casting method in this paper. The microstructures of the two alloys after hot compression at 350–500 °C and strain rate of 0.002–1 s−1 were studied, and the critical strain of dynamic recrystallization was calculated. It is found that the critical strain of dynamic recrystallization decrease because of Sm addition. Therefore, the Mg-8Gd-3Sm-0.5Zr alloy recrystallizes easily. Due to the addition of Sm, more dynamic precipitates (β) are produced in Mg-8Gd-3Sm-0.5Zr alloy during hot compression. The β phase increases the dynamic recrystallization nucleation rate and refines the dynamic recrystallized grains. The dynamic recrystallization mechanism of Mg-8Gd-3Sm-0.5Zr alloy are continuous dynamic recrystallization (CDRX) and particle stimulated nucleation (PSN).