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

The mixing enthalpy (Delta H), 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 Delta H, 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).