The influence of alloying on recrystallization behavior and texture development of Mg-(Ca, Zn) alloys

The influence of alloying Mg with Ca and Zn on the microstructural and texture evolution of binary Mg-2Zn (wt.%) and Mg-0.5Ca (wt.%) during static recrystallization (SRX) was systematically quantified using in situ techniques. In situ heating experiments were conducted inside of a scanning electron microscopy (SEM) equipped with an electron backscatter diffraction (EBSD) detector and a heating stage to track the nucleation and growth of strain-free grains throughout the entire annealing process. This enabled the sequential mapping of specific regions of interest throughout the recovery and recrystallization processes. In Mg-2Zn, deformation was accommodated mainly through extension {1012} twinning and {1011− 1012} and {1013− 1012} double twinning. These twin interfaces and twin nucleation sites along grain boundaries served as preferential sites for the nucleation of recrystallized grains. Additionally, the deformed texture was retained even after recrystallization due to the new grains inheriting the orientation of the twinned grains. In Mg-0.5Ca, multiple twinning systems were activated such as extension {1012} twinning, {1011} and {1013} contraction twinning, and {1011− 1012} and {1013− 1012} double twinning. Contraction and double twins served as preferred nucleation sites for recrystallized grains due to the higher strain energy generated within these regions. With more nucleation sites available within the Mg-0.5Ca microstructure, the resulting recrystallized crystallographic orientation exhibited a weaker texture compared to Mg-2Zn.