Multiphase‐Field Modeling of Discontinuous Dynamic Recrystallization

Solid‐state processing techniques such as friction extrusion and friction surfacing have emerged as advanced methods for processing metallic alloys. These techniques utilize frictional heat and severe mechanical deformation to drive microstructure changes without reaching the melting point. However, the severe thermo‐mechanical conditions during such processes make experimental characterization of microstructure evolution challenging. To address this, numerical modeling becomes essential for predicting microstructure behavior and guiding process optimization. This study presents a computational framework based on the multiphase‐field (MPF) method to investigate the discontinuous dynamic recrystallization (DDRX) mechanism occurring during these processes. The MPF method is utilized to model grain nucleation and boundary migration, incorporating the effects of dislocation dynamics through the implementation of the Kocks–Mecking model. This framework establishes a direct correlation between microstructure evolution and the macroscopic mechanical behavior observed during DDRX.