Abstract Scope |
The Lee-Robertson-Birnbaum criterion, the most common criterion for predicting the slip system of a transmitted dislocation, employs slip trace orientation, residual Burgers vector, and resolved shear stress. The general reliability of this criterion has been supported by experiment and simulation. However, existing simulations examine transmission due to the interaction of a grain boundary with a single dislocation, while in reality transmission is often due to the interaction of a grain boundary with a pileup of dislocations. The present work develops an atomistic simulation algorithm for creating shear dislocation loops sequentially and driving the loops toward a grain boundary, creating a dislocation pileup and ultimately inducing transmission. The algorithm is applied to a low angle Σ257 grain boundary and a high angle Σ185 grain boundary in aluminum to investigate the role of the number of dislocation loops in the pileup, magnitude of resolved shear stress, and choice of incoming slip system. |