Modeling of the viscosity in the AL-Cu-Mg-Si system: Database construction

The viscosity database for the Al-Cu-Mg-Si system was constructed using the CALPHAD (CALculation of PHAse Diagram)-type formalism. Viscosities of pure elements were described with the Arrhenius formula based on the experimental data. Subsequently, viscosities of the Al-Cu, Al-Si, Al-Mg and Cu-Si binary systems were assessed via CALPHAD technique and compared with the corresponding experimental data. Due to the lack of experimental data, viscosities in the Mg-Si and Cu-Mg systems were estimated by means of the Hirai's equation. The viscosities of the ternary Al-Cu-Si system were then predicted based on the binary parameters and compared with the experimental results. Using the established viscosity database for the quaternary Al-Cu-Mg-Si system, the viscosities of some commercial aluminum alloys were predicted. The reasonable agreement between calculations and experiments in Al-rich corner indicates that the CALPHAD-type database for the viscosity is valid and the database is suitable for predicting the viscosity of the commercial Al-Cu-Mg-Si based alloys.