Dislocation ↔ twin transmutations during interaction between prismatic slip and { 10 1 ¯ 1 } twin in magnesium

Very unusual and interesting interaction between matrix prismatic dislocations and { 10 1 ¯ 1 } twin boundaries (TBs) in Magnesium (Mg) was observed in atomistic simulations. When the first prismatic dislocation impinged on the TB, the incoming dislocation was transmuted into a thin layer of { 11 2 ¯ 1 } twin inside the { 10 1 ¯ 1 } twin. When successive prismatic dislocations on the same slip plane impinged on the same location at the { 10 1 ¯ 1 } TB, the { 11 2 ¯ 1 } twin kept growing toward the opposite { 10 1 ¯ 1 } TB. Eventually, the { 11 2 ¯ 1 } twin reached the opposite TB and was then transmuted back to prismatic dislocations that exited the { 10 1 ¯ 1 } twin and glided into the matrix. Hence, the matrix prismatic dislocations temporarily lose their dislocation identity during twin-slip interaction and then resume their dislocation identity after the interaction is complete. The net effect of these interactions is that the matrix prismatic dislocations transmit across the { 10 1 ¯ 1 } twin. Lattice correspondence analysis for { 10 1 ¯ 1 } twinning was performed to understand the mechanism of the interactions. The results show that, the prismatic slip plane is exactly the corresponding plane of { 11 2 ¯ 1 } twinning. Such a correspondence is consistent with the crystallographic calculations based on classical twinning theory.