The twin boundary interfacial structure and the configuration of zonal twinning dislocations for {10•1}<10•2> twin growth in magnesium were investigated by using molecular dynamics simulations and transmission electron microscopy. The simulation results show that twin growth was initially dominated by the motion of existing twin boundary steps. After these steps, the twin growth was mediated by the nucleation and glide of new zonal dislocations at the twin boundaries. The steps and the twinning dislocations have Burgers vectors of 1bT, 2bT and 4bT, where bT = 1/4•1/2<10•¯2> was the Burgers vector of the elementary twinning dislocation. The favourable zonal dislocation was 2bT, which could be viewed as the 1/2•1/2<10•¯2> matrix dislocation spreading over two {10•1} layers to accomplish the twinning relationship across the twin boundary. The connection established between the twinning and the dislocation slip in the matrix was supported by transmission electron microscopic observations.

Zonal Dislocations Mediating {10¯11}<10¯1¯2> Twinning in Magnesium. B.Li, E.Ma: Acta Materialia, 2009, 57[6], 1734-43