Simulation of Dynamic Recrystallization in 7075 Aluminum Alloy Using Cellular Automaton

The evolution of microstructure during hot deformation is key to achieving good mechanical properties in aluminum alloys. We have developed a cellular automaton (CA) based model to simulate the microstructural evolution in 7075 aluminum alloy during hot deformation. Isothermal compression tests were conducted to obtain material parameters for 7075 aluminum alloy, leading to the establishment of models for dislocation density, nucleation of recrystallized grains, and grain growth. Integrating these aspects with grain topological deformation, our CA model effectively predicts flow stress, dynamic recrystallization (DRX) volume fraction, and average grain size under diverse deformation conditions. A systematic comparison was made between electron back scattered diffraction (EBSD) maps and CA model simulated under different deformation temperatures (573 to 723 K), strain rates (0.001 to 1 s-1), and strain amounts (30% to 70%). These analyses indicate that large strain, high temperature, and low strain rate facilitate dynamic recrystallization and grain refinement. The results from the CA model show good accuracy and predictive capability, with experimental error within 10%.