Effect of Precipitation on Dynamic Recrystallized Grain Size in a Magnesium Alloy

Magnesium, the lightest structural metal has specific tensile strength and rigidity superior to iron and aluminum showing a rising demand for use in the automotive industries to lighten the structure. But, magnesium and its alloys have limited ductility and poor formability at room temperature due to an insufficient number of operative slip and twinning systems associated with its hexagonal close packed structure. A fine grain structure and random texture can improve the ductility or formability. The aim of this work is to investigate the effect of precipitates on micro structure evolution during hot deformation of Mg-Al-Sn alloy. Mg-Al-Sn alloy has been designed using thermodynamic modeling software, FactSage, based on forming precipitates at deformation temperature of 300 °C. The formation of precipitates, mostly Mg₂Sn, during the dynamic recrystallization process may slow down the grain growth resulting in finer grain size and grain size homogenization.