Philosophical magazine. A/Philosophical magazine. A. Physics of condensed matter. Structure, defects and mechanical properties · 1993 · 55 citations · 21 references
Dislocation NucleationEngineeringSevere Plastic DeformationMechanical EngineeringWork HardeningFreeze-thaw CyclingGrain BoundariesMechanicsMicrostructure-strength RelationshipMaterials ScienceIce-water SystemPhysicsStrain LocalizationAtmospheric IcingSolid MechanicsIce MechanicsPlasticityDislocation GenerationMicrostructureDislocation InteractionStructural GeologyApplied PhysicsIce-structure InteractionGrain Boundary PlaneMechanics Of Materials
Dynamic in situ X-ray topographic deformation studies have been performed on polycrystalline ice. Based on these observations, a new and dominant mechanism for dislocation nucleation, which is related to stress concentrations observed in the vicinity of grain boundaries, is proposed. It was found that the areas near grain boundaries always deform before the grain interiors. Lattice dislocations were nucleated continuously at large-angle grain boundaries, driven by internal stresses that are higher than the external stress. The dislocations, once generated, glide on the basal plane as semi-hexagonal loops. The shape of these loops is a result of a balance of the stresses present. The dislocation generation mechanism at grain boundaries was found to depend strongly on the basal plane orientation relative to both the loading direction and the grain boundary plane.
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Sliding behaviour and dislocation structures in aluminium grain boundaries
Hiroyuki Kokawa, Tadao Watanabe, Seiichi Karashima · Philosophical magazine. A/Philosophical magazine. A. Physics of condensed matter. Structure, defects and mechanical properties · 1981 · 223 citations
Materials Science, Engineering, Severe Plastic Deformation +15