Thermodynamic, Structural and Surface Properties of Cd-Na Alloys in Liquid State

Abstract

The Redlich–Kister polynomial equation was employed to optimize the temperature-dependent interaction parameters for excess Gibbs energy of mixing of the Cd-Na binary liquid alloy, utilizing experimental data on enthalpy and excess entropy of mixing. These parameters were used to evaluate thermodynamic properties such as Gibbs energy of mixing, enthalpy of mixing, and component activity in alloys at 673 K, 773 K, and 873 K. Structural properties like concentration fluctuations in the long wavelength limit and Warren–Cowely short range order parameter were also studied using these parameters. The Butler equation with interaction energy parameters was used to study the surface tension and surface composition of the alloys at the aforementioned temperatures. Experimental results confirmed the predicted values of excess Gibbs energy of mixing, enthalpy of mixing, and activity of mixing. Additionally, the excess Gibbs energy of mixing value changed from positive to negative with increased Cd compositions in the alloy. The enthalpy of mixing of the alloys was negative for all compositions. The concentration fluctuation in the long wavelength limit shifted toward optimal values at high temperatures. The surface tension of the alloys increased non-linearly with the bulk composition of Cd.