Effect of inhomogeneous deformation on the recrystallization kinetics of deformed metals

Abstract

In this paper, the Johnson-Mehl-Avrami-Kolmogorov equation, modified by Rollett et al. (1989) to take the heterogeneity of recrystallization into account, was used to derive analytical equations to calculate the instantaneous and average Avrami exponent during the heterogeneous recrystallization process. The model can explain experimental observations, such as a lower exponent than predicted by the JMAK theory and a decreasing exponent with proceeding recrystallization; moreover, by building up a quantitative relationship between local strain variation and heterogeneity of recrystallization kinetics, it can also describe so-far unex-plained observations, such as the range of experimentally observed exponents in recrystallization, and the very small effect of temperature and deformation conditions on the Avrami exponent.