Atomistic simulations of tension properties for bi-crystal copper with twist grain boundary

Abstract

Molecular dynamics simulation using an EAM potential to explore the tension response for a nanowire with a twist grain boundary (GB) is presented in this paper. The relationship between the GB strength and the interface dislocation structure is discussed. For a low angle twist GB, partial dislocations nucleate from the screw dislocation at the GB before yielding and the interface yields at the point when the dislocation networks lose their stability. For a high angle twist GB, the interface yields at the point when the whole interface structure is disturbed and partial dislocations propagate into the grain after the yielding point. In addition, the study provides an insight into the understanding of the atomic mechanism for tension localization at the GB, which is obvious for the high angle twist GB, but indistinct for the low angle twist GB. The results presented may have obvious implications for the nanowire test.