Calculation of phase diagrams and solidification paths of Al-rich Al−Li−Cu alloys

Thermodynamic models for the various phases in the Al-rich corner of the Al−Li−Cu system were developed on the basis of the phase equilibrium and limited thermodynamic data available in the literature and the thermodynamic descriptions of the three consitituent binary systems, Al−Li, Al−Cu, and Cu−Li. The calculated isothermal section at several temperatures and the liquidus projection are in ageement with the experimental determinations. Combining the thermodynamic models and the Scheil model or the modified Scheil model to incllude solidstate back-diffusion, quantitative solidification paths were predited. The calculated amount of the primary phase formed during solidification was compared with those obtained experimentally.