Multi-phase-field simulations for dynamic recrystallization

A dynamic recrystallization multi-phase-field (MPF-DRX) model that can approximately take into account grain deformation during dynamic recrystallization (DRX) has been developed, where the grain deformation was introduced by changing the size of a finite difference grid so as to keep the volume constant. The accuracy of the developed model was confirmed by simulating a single DRX grain growth. As a result of MPF-DRX simulations with grain deformation, it was clarified that, from microstructure evolutions, the appropriate deformation during DRX can be reproduced by the developed model. However, it was also concluded that the macroscopic stress–strain relationship and variations in grain size are not affected by the grain deformation introduced here. Furthermore, the DRX cycle was defined and the relationship between the DRX cycle fraction and the stress–strain curve was discussed. As a result, it was concluded that the stress–strain curve with multiple peaks is observed when the strain at the first valley of the stress–strain curve is smaller than that corresponding to the maximum first DRX cycle fraction.