Mesoscale simulation of interfacial microstructure evolution and healing mechanism manufactured by solid state bonding for metals during isothermal treatment

This study presents a mesoscale cellular automata (CA) model integrated with fundamental metallurgical principles to simulate the microstructural evolution and bonding mechanism of SA508-3 steel joints manufactured by solid state hot compression bonding during isothermal treatment. Metallurgical phenomena associated with isothermal treatment, such as static recrystallization (SRX), static recovery (SRV), and meta-dynamic recrystallization (MDRX) are described using dislocation density-based metallurgical laws. Utilizing this microstructure-integrated model, grain morphology, average grain size, and interfacial bonding ratio are quantitatively characterized during isothermal treatment. Furthermore, effects of isothermal temperature and pre-strain on the recrystallization behavior and interfacial bonding ratio are investigated by the proposed CA model, revealing that isothermal temperature significantly influences microstructural evolution and bonding ratio, whereas pre-strain has a relatively minor impact. The model demonstrates reliable predictive capability for average grain size, validated by comparison with experimental data, thus providing insights into the complex recrystallization processes during isothermal treatment and enabling quantitative predictions of microstructural evolution and bonding quality in SA508-3 steel solid state bonding joints.