Thermodynamic assessment of the Al-Cu-Zn system, part II: Al-Cu binary system

The thermodynamic description of the Al-Cu system is reassessed, and for the first time all available experimental data have been comprehensively compared with calculated results. Key distinctions from previous Calphad descriptions are worked out. The new model for the γ1 and γ2 phases partially reflects the crystal structure while being sufficiently simple for a realistic joining with the γ-CuZn phase in the Al-Cu-Zn ternary system. The η1/η2 phase transition and the α2 phase have been introduced in the description for the first time. An improved agreement of the calculated phase diagram with experimental data, very good agreement with the extensive thermodynamic properties of the liquid phase and reasonable agreement for solid phase thermodynamic properties is demonstrated.