Kinetics and size effect of grain rotations in nanocrystals with rounded triple junctions

A kinetic model is developed to quantify the rate of grain rotations driven by either grain boundary energy or stress. The critical roles of triple junctions and grain shape are emphasized. The size effects for the rotation rate are analyzed. As the grain size decreases, the model predicts shifts in the dominating driving forces and dissipation mechanisms. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.