Thermodynamic and microscopic structure of liquid Cu–Sn alloys

The observed asymmetry in the properties of mixing of Cu–Sn alloy in molten state is successfully explained on the basis of regular associated solution model. We have determined the free energy of mixing, heat of mixing, entropy of mixing, activity, concentration fluctuations in long wavelength limit SCC(0) and the Warren Crowley short-range parameter α1 of Cu–Sn alloys in molten state at 1400 K. The analysis suggests that heterocoordination leading to the formation of complex Cu3Sn is likely to exist in the liquid but is of a weakly interacting nature. The theoretical analysis reveals that the pairwise interaction energies between the species depend considerably on temperature and the alloy is more ordered towards Cu-rich region. Most of the thermodynamic parameters are found to be in good agreement with experimental values.