On the temperature dependence of the enthalpies of mixing in liquid binary (Ag,Cu,Ni)-Sn alloys

The partial and integral enthalpies of mixing of liquid binary alloys in the systems Ag-Sn, Cu-Sn and Ni-Sn were determined at different temperatures using drop calorimetry techniques. The data were fitted using a Redlich-Kister polynomial and the binary interaction parameters were evaluated. For all three systems the enthalpy curves are discussed focusing on the association theory. For selected curves Creg, Cass and the K-value were determined. The new results are discussed based on a compilation of literature data. The general shape and supposed temperature dependence of the enthalpy of mixing in Ag-Sn and Cu-Sn could be confirmed. No significant temperature dependence could be found for Ni-Sn at temperatures above 1100 °C. Our measured values fit well to most of the hitherto reported results. A second series of measurements limited to low concentrations of Ag, Cu or Ni, respectively in tin has been performed in order to determine the partial enthalpies of mixing at infinite dilution at 500, 600, 700, and 800 °C. Temperature dependence could be observed for all three binary systems, most developed for Ni-Sn.