Effect of Zn and Y Additions on Grain Boundary Movement of Mg Binary Alloys During Static Recrystallization

Texture evolution in rolled Mg-1 wt%Zn and Mg-1 wt%Y binary alloys was analyzed by quasi-in situ electron backscatter diffraction(EBSD)during static recrystallization.Mg-1 wt%Zn and Mg-1 wt%Y alloys exhibited strong basal texture at the initial recrystallization state.After grain growth annealing,the basal texture component{0001}<1120>was increased in Mg-1 wt%Zn alloy and that of Mg-1 wt%Y alloy was decreased to be a random texture.Zn and Y atoms segregated strongly to the recrystallized grain boundaries in Mg-1 wt%Zn alloy and Mg-1 wt%Y alloy,respectively.Thus,Zn and Y elements facilitated the grain boundary movements along contrary directions during grain growth.In Mg-1 wt%Zn alloy,due to the Zn element segregation on grain boundaries,the grains consisted of a strong texture grew more easily because the grain boundary migration tended to move from the orientation close to normal direction to the orientation near to transverse direction or rolling direction.Therefore,after grain growth,the volume fraction of texture component{0001}<1120>was increased by consuming the neighboring grains,leading to a stronger basal texture.On the contrary,in the Mg-1 wt%Y alloy,the Y element segregation caused the opposite direction of grain boundary migration,resulting in a random texture.