Orientation and rate dependence of dislocation nucleation stress computed using molecular dynamics

Molecular dynamics simulations are used to investigate orientation and rate dependence of partial dislocation nucleation in Cu. As the strain rate is reduced from 10(9) to 1(0)7 s(-1), the tensile stress required for homogeneous dislocation nucleation is reduced by at most 5%. Furthermore, mild orientation sensitivity is observed in the rate dependence of the critical tensile stress. The computed resolved shear stress for partial dislocation nucleation is consistent with previous ab initio calculations of the theoretical shear strength of Cu. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.