Microstructural path modeling of primary recrystallization

Abstract

While the classic KJMA model is frequently used to fit experimental recrystallization kinetics data, the fitted values in most cases are inconsistent with the observed microstructural evolution. In this paper, we review the much more powerful microstructural path modeling (MPM) methodology. A basic assumption in this next generation of recrystallization models is related to the spatial distribution of nucleation sites, which may be uniform in the mathematical sense, i.e. randomly distributed in the sample volume, or clustered either along lines or on planes. For example nuclei are often observed to be linearly aligned because they have formed along original grain boundaries or stringers of second phase particles in the deformed matrix. In this paper, we present a new MPM, which is extending the former idealized linear MPM, allowing the recrystallizing grains to grow with different speeds in different directions, thus becoming prolate spheroid shaped. Finally issues concerning experimental determination and analysis of growth rates, are discussed.