Phase equilibria of the La–Ni–Cu ternary system at 673 K: Thermodynamic modeling and experimental validation

Phase equilibria and thermodynamic properties in the La–Ni–Cu ternary system were studied by coupling thermodynamic modeling and experimental validation. A set of self-consistent thermodynamic descriptions for phases in the La–Ni–Cu system were obtained on the basis of those three constituent binary and ternary experimental data in the literature. The isothermal section at 673 K and the mixing enthalpy of liquid calculated from the currently constructed ternary thermodynamic description were favorably compared with available experimental data. Three key alloy samples were then selected, synthesized and annealed at 673 K in order to further validate the calculated phase equilibria. These alloys were analyzed by means of inductively coupled plasma (ICP), X-ray diffraction (XRD), scanning electron microscopy (SEM)/back-scattered electrons (BSE) and energy disperse spectroscopy (EDS), and the experimental results were in reasonable agreement with the calculated phase equilibrium relationships.

► The enthalpy of mixing of liquid was thermodynamically assessed using the Calphad method. ► The isothermal section at 673 K is thermodynamically calculated and experimentally validated. ► The LaNi and LaCu2 two-phase field was larger than that reported in the literature.