Study on the paired twinning behavior in a hot rolled AZ31 magnesium alloy via interrupted in situ compression

摘要

Continuous {1012} twin bands across neighboring grains was observed in a hot rolled AZ31 during the interrupted compression along the rolling direction. The variant selection in paired twins was studied by Schmid factor (SF) and geometric misorientation relationship. The results show that most mated twins possess high rank Schmid factors (SFs), however, they does not share the same twin variant. Furthermore, EBSD analysis indicates that the formation of paired twins is correlated with the orientation relationship between adjacent grains. Based on these observation and analysis, the mechanism of "sequential twinning" nucleation and synergetic growth during deformation are proposed. Above all, this twinning behavior is capable of transmitting the localized shear and releasing stress at the former twin-termination interfaces, which plays an important role in accommodating plastic strain and mediating multiple grains' deformation.