Understanding the dynamic recrystallization behaviors of a hot-rolled Mg-1.0wt%Ca plate by compressing along different original orientations

The effects of original orientations on the dynamic recrystallization (DRX) behaviors of a hot-rolled Mg-1.0wt% Ca plate were investigated in this work. Using hot compression along the rolling direction (RD) and the normal direction (ND) at 400 degrees C, 430 degrees C and 460 degrees C, the microstructural and textural evolutions closely related to the DRX behaviors were analyzed in detail. At the same temperature, DRX occurred more easily in the ND sample. But as the compressive temperature increased, both the area fraction and the size of the DRXed grains improved faster in the RD sample. During hot compressing, very few dislocations persisted in the DRXed grains of the RD sample and the discontinuous DRX mechanism was confirmed. Differently, dislocation tangles composed the grain boundaries of the DRXed grains of the ND sample and the continuous DRX mechanism was confirmed. Besides, compared to commercial Mg alloys such as ZK60 and AZ31, Mg-1.0wt%Ca alloy significantly postponed both the continuous DRX and discontinuous DRX processes. The Mg-Ca based alloys with great microstructural stability now offer more possibilities for developing high creep-resistant and high burn-resistant Mg components with free rare-earth addition.

Automated summary

The effects of original orientations on the dynamic recrystallization behaviors of a hot-rolled Mg-1.0wt% Ca plate were investigated. It was found that dynamic recrystallization occurred more easily in the normal direction sample at the same temperature. As the temperature increased, the area fraction and size of the dynamic recrystallized grains improved faster in the rolling direction sample. The Mg-1.0wt%Ca alloy significantly postponed both the continuous and discontinuous dynamic recrystallization processes compared to commercial Mg alloys.