Thermodynamic analysis of Al–Sc, Cu–Sc and Al–Cu–Sc system

Encouraged by the promising application of the Al–Cu–Sc system in the development of high strength aluminum alloy, the Al-rich region of this system was assessed by the CALPHAD approach. In order to make the models used for the phases in the three binary sub-systems compatible with each other, Al–Sc and Cu–Sc system were remodeled. Substitutional solution model was used for solution phases and sublattice model for binary intermetallic phases and the ternary compound Al8−xCu4+xSc. Comparisons between the calculated and experimental results showed that most of the experimental information was satisfactorily described by the present thermodynamic description.