Molecular dynamics and molecular statics simulations were performed to simulate the motion of a screw dislocation and its interaction with voids in irradiated body-centered cubic Mo. Considering the unique non-planar core structures of the screw dislocation in body-centered cubic metals, the behavior of screw dislocation motion as a function of temperature and applied shear stress was first discussed. A transition from smooth to rough motion of the screw dislocation was observed with increasing shear stress, as well as a change of dislocation glide plane from {110} to {112} with increasing temperature. The interaction of a screw dislocation with nanometer-sized voids observed in both dynamic and static conditions was then reported. The obstacle strength calculated from molecular statics calculations showed a large increase in critical resolved shear stress for void diameter larger than about 3nm. However, the molecular dynamics results indicated that the screw dislocation interaction with voids occurred via a simple shear mechanism.

Molecular Dynamics Simulation of Dislocation–Void Interactions in BCC Mo. H.J.Lee, B.D.Wirth: Journal of Nuclear Materials, 2009, 386-388, 115-8