3D Discrete Dislocation Dynamics Applied to Interactions between Dislocation Walls and Particles

A 3D discrete dislocation dynamics model is presented that describes dislocation processes in crystals subjected to mechanical loadings at high temperatures. Smooth and curved dislocations are approximated by a set of short straight line segments. A Peach-Koehler force acting upon each segment involves all segment-to-segment interactions and externally applied stress. The segment velocity is a product of a corresponding mobility and the glide or climb component of the Peach-Koehler force. The model addresses interactions between dislocations and rigid spherical precipitates. A migration of low angle tilt boundaries situated in a field of precipitates is simulated as an example. The numerical implementation exploits symmetries of the model that yield an optimized and highly efficient numerical code. Results provide detailed insight into how dislocation arrangements surmount particle fields in 3D crystals.