The relative importance of nucleation vs. growth for recrystallisation in particle-containing Fe3Al alloys

Recrystallisation behavior was studied in two Fe3Al-based alloys containing both large and fine particles with a different fine particle dispersion level using high-resolution SEM and EBSD. High misorientation of 15-30 degrees was created around large particles after a hot rolling process in the two alloys. The kinetics of recrystallisation were, however, considerably retarded in the alloy containing dense fine particles. It was observed that the growth of subgrains created around the large particles was inhibited by the presence of the fine particles. This result clearly suggests that when the particle density (N-s) is high relative to local stored energy (E) around large particles, nucleation can be completely hindered. As the N-s/E level decreases, nucleation may occur and the kinetics of recrystallisation might be determined by both the nucleation rate and the growth of nuclei into a matrix with fine particles.