Orientation dependence of the nucleation and growth of partial dislocations and possible twinning mechanisms in aluminum

摘要: Abstract Plastic deformation in certain nanocrystalline metals (grain size less than 100 nm) or under conditions is associated with profuse activation of partial dislocations grain boundaries acting as both the source and sink. We use molecular dynamics (MD) simulations pure aluminum to investigate orientation dependence mechanisms, show that two types twins can be generated. Theoretical calculations are used understand effect loading on twins. The theoretical framework incorporates (a) a tensorial stress state, (b) dislocation loops (c) non-singular core energies for accurate descriptions criteria activation. Both predictions MD simulation demonstrate should possible (but rare) aluminum.