Unravelling the nucleation and growth of {11-(2)over-bar2} twins

A recently proposed mechanism of {11 <(2) over bar > 2} twin nucleation in Ti by reverse phase transformation is analysed. It is demonstrated that, not only nucleation, but also growth mechanism of an already formed twin is connected to the possibility of the phase transformation in the system, which leads to the existence of several competing structures of twin boundary. The twin growth is mediated by subsequent glide of step-like defects (disconnections) along the {1122} boundary. The twin shear is completed by gliding of pair of disconnections, which also converts twin boundary structure between two alternative variants.

Automated summary

This study analyzes the recently proposed mechanism of {11 <(2) over bar > 2} twin nucleation in Ti by reverse phase transformation, showing the connection between nucleation and growth mechanism of twins with the possibility of phase transformation. The process involves the gliding of step-like defects along the {1122} boundary to mediate twin growth, with the shear of twins completed by the gliding of disconnections that convert the twin boundary structure between alternative variants.