Revealing curvature and stochastic effects on grain growth: A thermodynamic perspective from extremal principle

In the theoretical analysis of grain growth kinetics, the roles of curvature and stochastic effects have been an open question for many years. Considering contributions of microstructure entropy and a phenomenological grain topological energy, the present work develops a thermodynamic dissipation-based framework for representing the stochasticity and spatial correlations in grain growth. This framework reveals the correlations between previous mean-field and stochastic theories, whose validities are further assessed by the 3-D Aboav-Weaire relationship.