Experimental investigation and thermodynamic assessment of the Ag–Cr–Y and Ag–Cu–Y ternary systems

Abstract

The phase equilibria of the Ag–Cr–Y system were investigated by a combination of key experiments and thermodynamic modeling. Eleven ternary alloys were prepared to determine the isothermal sections of the Ag–Cr–Y system at 500, 600 and 800 °C, by means of X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS). No ternary compound was found in the Ag–Cr–Y system. Based on the experimental phase equilibria data, thermodynamic assessment of the Ag–Cr–Y and Ag–Cu–Y systems was performed by the CALPHAD (CALculation of PHAse Diagrams) method. Two ternary compounds τ1 and τ2 in the Ag–Cu–Y system with the compositions of Ag3Cu12Y5 and (AgxCu2-x)Y (x: 22.9–43.1 at.%) were described by two sublattice model (Ag, Cu)4Y1 and (Ag, Cu)2Y1, respectively. A set of self-consistent thermodynamic parameters of the two systems were obtained. Most of the reliable experimental data can be well reproduced by the present thermodynamic modeling.