Calculation of Thermodynamic Properties of Cu-Ce Binary Alloy and Precipitation Behavior of Cu₆Ce Phase

Abstract

The mixing enthalpy (ΔH), the excess entropy (S_AB^E), the excess Gibbs free-energy (G_AB^E) and the component activities (a) of Cu-Ce binary alloy system were calculated based on Miedema’s model and some general thermodynamic relations. Results showed that the values of ΔH, S_AB^E, and G_AB^E of Cu-Ce binary alloy in 1555 K were all negative in the whole range concentration. The activities of Cu and Ce had negative deviation from Raoult’s Law, which indicated that there was a strong interaction between Cu and Ce. The calculation results of the mixing enthalpies and the activities of Cu and Ce agreed well with the experimental results. Cu₆Ce phase precipitation behavior in thermodynamics and dynamics were also discussed. Furthermore, combining the experiment, the existence of Cu₆Ce phase particles was observed using scanning electron microscopy (SEM) and energy dispersion spectrometry (EDS).