GRAIN BOUNDARY, TRIPLE JUNCTION, AND QUADRUPLE POINT GRAIN GROWTH DYNAMICS

摘要

Grain boundaries, triple junctions, and quadruple points are the geometrical elements in 3-D polycrystalline networks, where these elements have co-dimensions 1, 2, and 3, respectively. Grain boundary mobility usually controls network kinetics in materials with "large" grain sizes. Nonetheless, there are studies concerning the effects of these network elements on the self-similar distributions of scaled grain size and number of faces per grain. This study applies a polyhedral representation of grains that the authors developed previously to obtain LSW-like (self-similar) behavior for distributions with three rate-limiting situations, viz., where the kinetics of network evolution is controlled by boundary, triple junction, or quadruple point mobility. The self-similar network states so obtained yield important implications concerning details of polycrystalline evolution, such as grain growth "trajectories", grain lifetimes, and their volume-time behavior.