Application of computational thermodynamics to the determination of thermophysical properties as a function of temperature for multicomponent Al-based alloys

• A model coupled to a computational thermodynamics software is proposed to compute thermophysical properties.
• The model applies to multicomponent alloys and has been validated against experimental results.
• Density and specific heat as a function of temperature are computed for Al–Si–Cu alloys.

Despite the technological importance of Al–Si–Cu alloys in manufacturing processes involving heat transfer, such as welding, casting and heat treatment, thermophysical properties of this system of alloys are very scarce in the literature. In this paper, a model connected to a computational thermodynamics software is proposed permitting density and specific heats as a function of temperature and enthalpy of transformations to be numerically determined. The model is pre-validated against experimental density as a function of temperature for liquid and solid phases of A319 and 7075 alloys found in the literature and validated against experimental density values for the solid phase of an Al-6 wt%Cu-1 wt%Si alloy determined in the present study. In both cases the numerical predictions are in good agreement with the experimental results. Specific heat and temperatures and heats of transformation are also numerically determined for this ternary Al-based alloy.