Mesoscopic analysis of structure and strength of dislocation junctions in fcc metals

Abstract

We develop a finite-element-based nodal dislocation dynamics model to simulate the structure and strength of dislocation junctions in fcc crystals. The model is based on anisotropic elasticity theory supplemented by the explicit inclusion of the separation of perfect dislocations into partial dislocations bounding a stacking fault. We demonstrate that the model reproduces in precise detail the structure of the Lomer-Cottrell lock already obtained from atomistic simulations. In light of this success, we also examine the strength of junctions culminating in a stress-strength diagram which is the locus of points in stress space corresponding to dissolution of the junction.