Configuration of dislocations in low-angle kink boundaries formed in a single crystalline long-period stacking ordered Mg-Zn-Y alloy

Abstract The dislocation configuration around low-angle kink boundaries formed in bent single crystalline long-period stacking ordered (LPSO) Mg85Zn6Y9 alloys was investigated. Intragranular misorientation axis (IGMA) analysis through SEM/EBSD observation and g•b analysis through TEM observation were conducted. Various kink bands possessing different lattice rotation axes ranging from 1 1 ¯ 00 > to 1 2 ¯ 10 >, i.e. along 1 1 ¯ 00 >, , and 1 2 ¯ 10 > were revealed using IGMA analysis. TEM observation with g•b analysis unveiled that the 1 1 ¯ 00 >-rotation kink boundary observed using IGMA analysis consisted of basal edge dislocations with one Burgers vector, while the 1 2 ¯ 10 >/ -rotation kink boundaries were comprised of basal edge dislocations with more than one Burgers vector. Low-angle kink boundaries were regarded as low-angle tilt boundaries consisting of perfect basal dislocations, regardless of their rotation axes. The formation of various kink bands with -combination-rotation axes ranging from 1 1 ¯ 00 > to 1 2 ¯ 10 > suggests that the statistically stored basal dislocations may turn into geometrically necessary basal edge dislocations during the initial stage of low-angle kink boundary formation. When a kink boundary is considered as a disclination, IGMA analysis capable of determining the lattice rotation axis and the angle is effective in evaluating the Frank vector of the kink boundary.