Phase-field simulation of recrystallization based on the unified subgrain growth theory

The effects of the microstructural inhomogeneities created in the deformed state on recrystallization kinetics have been investigated by using phase-field (PF) simulations. Numerical simulations of static recrystallization have been performed in two-dimensional polycrystalline structures by coupling the unified subgrain growth theory with PF methodology. Simple assumptions based on experimental observations have been utilized for preparing the initial microstructures. The following results have been obtained: (1) The transition from continuous to discontinuous recrystallization is successfully reproduced by simulations in which the inter-subgrain misorientation, 〈 θ 〉, varies and the initial mean subgrain radius, 〈 R₀ 〉, and the total number of pre-existing grains, N, are kept constant. (2) For discontinuous recrystallization, the initiation occurred faster and the termination time reduced with a decrease in 〈 R₀ 〉. (3) We have confirmed that a significant increase in the fraction of high-angle grain boundaries suppressed the discontinuous recrystallization. (4) We have proposed microstructural entropy as an indicator of the discontinuity of recrystallization based on the subgrain size distribution.