Stress effects on atomistic kinetic transitions

Abstract

In this thesis, I studied how the full tensorial stress state applied to a kinetic transition impacts the activation enthalpy. To this end, the activation energy, scalar activation volume, and tensorial activation volume were studied for several kinetic transition types. This computational study used the nudged elastic band method to find the activation state for initial and final configurations known a priori, primarily from the kinetic activation relaxation technique. The preliminary work was verified by a commonly studied and well understood vacancy generation and migration to an adjacent lattice cite in FCC copper and HCP titanium. The method was then applied to transitions of increasing complexity: point defect generation in a perfect copper crystal, and grain boundary transitions in the [Sigma] 5 [210] grain boundary in copper.