Coupled CA-FE Simulation for Dynamic Recrystallization Microstructure Evolution of AZ61 Magnesium Alloy

The dynamic recrystallization (DRX) behavior during the thermal deformation process of AZ61 magnesium alloy was systematically studied using a combined finite element (FE) and cellular automaton (CA) model. Isothermal compression experiments on AZ61 magnesium alloy were conducted using a Gleeble-1500 thermal simulator at temperatures ranging from 300 to 450 ℃ and strain rates from 0.003 to 1 s⁻¹, obtaining true stress–strain curves under various deformation conditions. Based on the obtained experimental data, a high-precision physical constitutive model for AZ61 alloy was established, along with a DRX kinetics model and a recrystallization critical model. At the same time, the grain size model was established by measuring the microstructure of the alloy. In addition, the parameters of the CA model were found, and the dislocation density model for CA simulation was established on this basis. Simulation results indicated that the dynamic recrystallization behavior is influenced by deformation temperature, strain rate, and strain. The predicted DRX volume fraction and average grain size matched well with experimental results, with a maximum error of less than 8%, demonstrating the high accuracy of the established model. This validated the effectiveness and predictive prospect of the CA-FE coupled method, this method provides a powerful tool and theoretical guidance for studying the DRX microstructure evolution of AZ61 magnesium alloy during hot deformation.