Atomistic simulations of interactions between screw dislocation and twin boundaries in zirconium
(Institute of Engineering Mechanics, Beijing Jiaotong University, Beijing 100044, China)
Abstract: Molecular statics was employed to simulate interaction between screw dislocation and twin boundaries (TB) in hexagonal close-packed zirconium. In the moving TB model, the interaction of a moving TB with a static screw dislocation was investigated. Twinning dislocation (TD) nucleation and movement play an important role in the interaction. The screw dislocation passes through the moving TB and changes to a basal one with a wide core. In the moving dislocation model, a moving dislocation passes through the TB, converting into a basal one containing two partial dislocations and an extremely short stacking fault. If the TB changes to the one, the moving prismatic screw dislocation can be absorbed by the static TB and dissociated into two TDs on the TB. Along with the stress-strain relationship, results reveal the complicated mechanisms of interactions between the dislocation and TBs.
Key words: twin boundary; twinning dislocation; slip transfer reaction; athermal process