Optimization of Thermodynamic Properties of Liquid Au-Ni Alloys

Abstract

The best fitted values of the size ratio and the order energy parameter (W) have been used to calculate the thermodynamic properties of liquid Au-Ni alloys at temperature of 1150 K, using the Quasi-Lattice Theory. The temperature dependent values of order energy parameter were then used to optimize various thermodynamic properties such as the excess free energy of mixing, activity and activities coefficients of the components, partial excess free energy of mixing, the concentration-concentration fluctuations in long-wavelength limits, the heat of mixing, the entropy of mixing as well as the chemical diffusion at different temperatures. The positive deviations observed in various calculated thermodynamic properties and the microscopic functions, (Scc(0) and ) show that liquid Au-Ni alloy is a segregating system. The degree of segregation in the alloy is weak though. The values of W are positive and decrease as the temperature increases. These values of W and  were utilized in predicting the various thermodynamic properties of the liquid Au-Ni alloys at different temperatures.