Interaction between a Mg_(17)Al_(12) precipitate and {10(1-)2} < 10(1-2-) > twin boundary in magnesium alloys

摘要

Interactions between Mg_(17)Al_(12) precipitates and{10(1-)2} <10(11-) > twin boundaries (TBs) in magnesium werestudied by molecular dynamics simulations. The results obtainedagree well with experimental observations in which precipitatescan be entirely engulfed by {10(1-)2} <10(11-) > twins without beingsheared. Structural analysis of the TBs in the atomic scale showsthat the TBs are extremely incoherent during twin growth andhighly deviate from the {10(1-)2} twinning plane as previouslyobserved in a number of experiments. The simulation studiesindicate that {10(1-)2} <10(11-) > twinning was accomplished solelyby atomic shuffling that converts the parent lattice to the twinlattice without involving twinning dislocations, resulting in zeroshear strain at the TBs.