Experimental study and thermodynamic description of the Au-Cu-Ge system

Phase equilibria in the Au-Cu-Ge ternary system, including the solid state phase relations at 450 °C as well as four vertical sections, were studied by means of scanning electron microscopy (SEM), electron probe microanalysis (EPMA), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Based on the present experimental results and the available information in the literature, a thermodynamic description of the Au-Cu-Ge ternary system has been developed using the CALPHAD (CALculation of PHAse Diagram) method. A consistent set of thermodynamic parameters for each phase was derived. The calculated phase diagrams and thermodynamic properties are in reasonable agreement with the experimental data obtained in the present study as well as those reported in the literature.