J191052 Evaluation of Mechanical Behavior Change Due to Lattice Defects in Fine Grained Metal under Space Environment Based on Molecular Dynamics Method

Abstract

Considering space utilization of the fine-grained metals, we have investigated an influence of the nano-scale voids on mechanical behavior of Cu fine-grained metals based on molecular dynamics (MD) method. Focusing on the dislocation activity enhancement due to void growth, grain size and temperature dependence of the mechanical behavior change have been evaluated. MD simulations have shown the following results: (1) Dislocation activity around the void at the initial void growth stage has an influence on the change in yield stress. (2) Dislocation activity enhancement due to void growth during and after yielding conducts increased ductility by improved plastic deformability. (3) Amount of ductility enhancement is larger at low temperature than at room temperature.