Continuum Modelling of Shear-Coupled Grain Boundary Migration

摘要: The deformation accommodation mechanisms associated to grain boundaries (GBs) significantly affect the mechanical behavior of nano-polycrystals. Among these mechanisms, stress-induced GB migration is now seen compete or interplay with other intra-granular and in a wide range temperatures. A complete micromechanics-based model here proposed using concepts continuum thermodynamics kinematics derive new constitutive able describe migration. Like non diffusive phase-transformations, can be considered on point view conservative nature (diffusionless but thermally activated) until high temperature respect melting point. Here, framework micro-mechanics which should easily implemented polycrystalline model, we will first micromechanical framework: additive including plastic bulk crystals, sliding. For sake illustration present general theory, focus planar bi-crystals only perfect shear-coupling situations [001] symmetric tilt GBs Cu. Numerical examples responses are given for considering both isotropic anisotropic elasticity. These ones fed by computer-aided MD simulations identified.