Invited Lecture
Grain Boundary Structure and Grain Boundary Dynamics: migration, diffusion, point defect adsorption

Low angle grain boundaries can be described as arrays of dislocations and grain boundary dynamics can be described in terms of the motion of these dislocations; this includes grain boundary migration, point defect adsorption, diffusion, ... For higher angle and more general grain boundaries, this dislocation picture breaks down. However, the dynamics of such grain boundaries can be understood by consideration of disconnection dynamics. Disconnections are interfacial defects that are characterized by both a Burgers vector and an interfacial step height; which are constrained together by bicrystallography. I will first introduce the disconnection model and describe several boundary dynamical properties in a disconnection language. The remainder of the talk will focus on the interaction between disconnections, point defect sink/source behavior , and diffusion.