Multiscale modeling of dislocation/grain-boundary interactions: III. 60° dislocations impinging on Σ3, Σ9 and Σ11 tilt boundaries in Al

摘要: The interactions between 60° dislocation pile-ups with grain boundaries (GBs) are studied using multiscale modeling. Careful quantitative analyses of complex processes associated absorption and transmission phenomena at Σ3, Σ9 Σ11 symmetric tilt in Al interpreted terms a set modified Lee–Robertson–Birnbaum (MLRB) criteria. Our results the MLRB criteria (i) explain experimental observations, (ii) rationalize new mechanisms such as deformation twinning formation extended stacking faults, (iii) show that reactions can be controlled more strongly by leading partial an incoming rather than full Burgers vector (iv) demonstrate non-Schmid stresses, e.g. shear compressive stresses along GB, GB step-height changes on all influence critical nucleation stress, but to differing degrees among different boundaries. do not capture effects local structure also behavior. Quantitative metrics based formulated, simulation results, for various phenomena. These used input into mesoscale models discrete plasticity, so atomic-scale observations inform higher-scale predictions plasticity.