Molecular Dynamics Simulations of Dislocation Nucleation From Bicrystal Interfaces in FCC Metals

Atomistic simulations are used to study dislocation nucleation from <001> tilt bicrystal interfaces in copper subjected to a tensile deformation. Specifically, three interface misorientations are examined, including the Σ5 (310) interface, which has a high density of coincident atomic sites. The initial interface configurations, which are discussed in terms of structural units, are refined using energy minimization techniques. Molecular dynamics simulations are then used to deform each interface in tension. The role of boundary conditions and their effect on the inelastic deformation response is discussed in detail. Molecular dynamics simulations show that the interface structural units are directly involved in the partial dislocation nucleation process. The maximum tensile strength of the Σ5 (310) interface shows a modest increase in the case where lateral confinement of the interface is an important consideration.