Computer simulation of recrystallization-II. Heterogeneous nucleation and growth

Abstract

A two-dimensional Monte Carlo computer simulation technique, in which a continuum system is modeled employing a discrete lattice, has been applied to the problem of primary recrystallization. The stored energy is varied between levels allowing homogeneous nucleation and nucleation only on pre-existing grain-boundaries and grain-boundary vertices. The attempted nucleation rate is chosen as either constant rate or site saturated. Temporal evolution of the simulated microstructures are analyzed to provide the time dependence of the recrystallized volume fraction. The recrystallized volume fraction shows sigmoidal variations with time. The long time data are approximately fit by the Johnson-Mehl-Avrami-Kolmogorov equation with the expected exponents for the operative nucleation mechanism, however significant deviations are observed at early times. The recrystallized microstructures are analyzed to give the grain size distribution function and the topological distribution function (number of domain edges). Compared to grain growth microstructures, where the grain size is proportional to the number of edges, the recrystallized microstructure shows significant deviation from this relation. © 1988.