THERMODYNAMICS OF COMPOUND FORMING MOLTEN Cu–In ALLOYS

Abstract

A study of the thermodynamic properties of Cu in molten Cu – In alloys has been explained using a compound formation model. We use the model to deduce information on thermodynamic properties of the alloy such as the Gibbs free energy of mixing, the enthalpy and entropy of mixing. In this study, we first model the Gibbs free energy in terms of the interaction parameters. Sequel to this, the interaction parameters are utilized to quantify properties such as the concentration–concentration fluctuations in the long wavelength limit, the Warren–Cowley short-range order parameter, and the chemical diffusion. Both positive and negative deviations from Raoultian behavior and concentration-dependent asymmetry in the mixing properties of CuIn 4 liquid alloys were reported. Our analysis suggest that the liquid alloy undergoes a transformation from an ordered ( In -rich end) to segregating ( Cu -rich end) state. The system also exhibits ideal behavior at the Cu -rich end.