On the growth of abnormal grains

Abstract

This paper presents a contribution to the theory of abnormal grain growth in two dimensions by considering an idealized model with both a variable boundary energy and a variable mobility. The authors idealize the problem by considering a single A grain in a matrix of B grains where the AB boundary has a different energy and mobility from the BB boundaries. The analysis is based on the differential curvature rule which allows the boundary to have any shape between vertices which are assumed to be in equilibrium. The authors consider both the instantaneous growth rate of grain A, and the ultimate size of A relative to that of the B grains during grain growth. An extensive literature exists on abnormal grain growth; some of the recent investigations show the importance of variable boundary properties. Harase et al., for example, find that the boundaries of growing grains in secondary recrystallization in silicon steel have a higher frequency of coincidence site boundaries with low sigma ({Sigma} < 33) than is expected for randomly oriented grains.