Can nanoscale twin boundaries serve as dislocation sources in single crystals?

▸ Perfect twin boundaries (TBs) are not dislocation sources under homogenous deformation. ▸ Under inhomogeneous deformation TB steps and pinning stacking faults break the coherency of TBs, turning the TBs into potential dislocation sources. ▸ A much higher strength can be obtained by TB migration mechanism.