Sensitivity analysis of a phase field model for static recrystallization of deformed microstructures

Static recrystallization is a process whereby dislocation-free grains are nucleated in a deformed microstructure and then newly recrystallized grains grow and consume the previously existing grains. This paper describes a phase field model for static recrystallization, along with details of the implementation and simulation results. Recrystallized grains are seeded utilizing a probability-based method, including a hold time to allow the order parameters to adjust to seeded grains. The nominal simulation time is corrected to account for the nuclei hold and for the time required for a nucleus to grow from its critical size to the seeded size. Microstructural evolution was simulated for two- and three-dimensional systems and the fraction recrystallized was quantified via Avrami kinetics. The resulting Avrami time exponents were in agreement with the expected values for site-saturated nucleation. The variability in the Avrami parameters was quantified by simulating the recrystallization of the same underlying polycrystalline microstructure but using different seed locations. Additional simulations were performed to determine the influence of the deformed microstructure on recrystallization, specifically investigating the effects of the spatial distribution of the initial dislocation density within the microstructure as well as the morphologies of the polycrystalline microstructure. For the significantly deformed polycrystalline microstructures examined in this work, it is shown that microstructural evolution is primarily driven by stored energy in dislocations rather than grain boundary energy. (paper)