Chapter 92 Dislocations and Plasticity in bcc Transition Metals at High Pressure

摘要: Abstract Using first-principles electronic-structure calculations, quantum-based atomistic simulations, and atomistically informed dislocation dynamics (DD) we have studied individual behavior the multiscale modeling of single-crystal plasticity in prototype bcc transition metals Ta, Mo, V under both ambient high-pressure conditions. The primary focus this work is on pressure-dependent structure, mobility, interaction a/2〈1 1 1〉 screw dislocations, which dominate plastic deformation properties these materials. At electronic scale, calculations elasticity, ideal strength, generalized stacking-fault energy surfaces been used to validate multi-ion interatomic potentials. potentials flexible Green's function boundary condition simulations study core Peierls stress τP, thermally activated kink-pair formation mobility below phonon-drag above τP. These results then distilled into analytic velocity laws directly predictive microscale DD flow resolved yield over wide ranges pressure, temperature, strain rate.