An integrated approach to study the hot tearing behavior by coupling the microscale phase field model and macroscale casting simulations

Hot tearing is the serious defect that occurs in aluminum alloy castings. A constitutive model of the aluminum alloy mushy zone is vital for the accurate prediction of hot tearing and thermal stress. In this study, an integrated approach was developed to study the hot tearing behavior of cast aluminum alloys. The constitutive behavior and rheological properties of the solidifying aluminum alloys were determined using phase-field simulations and micromechanical calculations. Subsequently, an elastic–viscoplastic (E-VP) constitutive model was constructed for thermal stress analysis and hot tearing prediction. To verify the analysis results, constrained rod casting (CRC) experiments were performed using a permanent mold and a mushy zone deformation and hot tearing propagation mechanism was established based on the casting experiments results. The study indicates that the E-VP model, which is constructed based on the phase-field simulations and micromechanical calculations in this study, enables high-accuracy hot tearing predictions. Furthermore, the E-VP constitutive model is consistent with the deformation mechanism of the solidifying mushy zone. This work accomplished the comprehensive study on aluminum alloy castings ranging from microstructure simulation to hot tearing prediction, which provides a reference and integrated approach for multi-scale analysis in casting processing. • The study on aluminum alloy casting from microstructure simulation to hot tearing prediction was accomplished. • An integrated approach was developed to obtain the rheological properties of the solidifying aluminum alloys. • A mushy zone deformation and hot tearing propagation mechanism was established. • The E-VP model constructed in this paper enables higher accuracy in hot tearing prediction than the E-P model. • The rheological structure is a possible cause for the hot tearing severity decreases with increasing casting temperature.