Microstructural modelling of dynamic recrystallisation using an extended cellular automaton approach

Dynamic recrystallisation (DRX) governs the plastic flow behaviour and the final microstructure of many crystalline materials during thermomechanical processing. Understanding the recrystallisation process is the key to linking dislocation activities at the mesoscopic scale to mechanical properties at the macroscopic scale. A modelling methodology coupling fundamental metallurgical principles with the cellular automaton (CA) technique is here derived to simulate the dynamic recrystallisation process. Experimental findings of a titanium alloy are considered for comparison with theory. The model takes into account practical experimental parameters and predicts the nucleation and the growth kinetics of dynamically recrystallised grains. Hence it can simulate different stages of microstructural evolution during thermomechanical processing. The effects of hot working temperature and strain rate on microstructure were studied, and the results compared with experimental findings.