Effect of deformation twinning on crystallographic texture evolution in a Mg–6.6Zn–0.2Ca (ZX70) alloy during recrystallisation

The entire recrystallisation sequence and associated crystallographic texture evolution of Mg-6.6Zn-0.2Ca (ZX70, wt.%) alloy were tracked using a quasi-in-situ electron backscatter diffraction (EBSD) method. The commonly observed grain boundary recrystallisation in conventional Mg alloys was largely restricted, since all the prior grain boundaries were pinned by intermetallic compounds distributed along grain boundaries. A typical “Rare Earth” (RE) texture was observed during the whole recrystallisation process. The RE texture appeared during the nucleation stage because of RE texture orientations introduced by recrystallisation from double twins. This texture was retained during the subsequent grain growth stage because of uniform grain growth. Recrystallised grains induced by a considerable amount of intermetallic compounds did not change the leading role of double twins on contribution to recrystallised texture. All results indicate that a small amount of Ca addition into a conventional Mg-Zn alloy system can significantly alter the recrystallised texture from basal texture to RE texture.