Enthalpy of mixing of liquid systems for lead free soldering: Ni–Sb–Sn system

The partial and integral enthalpies of mixing of liquid ternary Ni–Sb–Sn alloys were determined along five sections x(Sb)/x(Sn) = 3:1, x(Sb)/x(Sn) = 1:1, x(Sb)/x(Sn) = 1:3, x(Ni)/x(Sn) = 1:4, and x(Ni)/x(Sb) = 1:4 at 1000 °C in a large compositional range using drop calorimetry techniques. The mixing enthalpy of Ni–Sb alloys was determined at the same temperature and described by a Redlich–Kister polynomial. The other binary data were carefully evaluated from literature values. Our measured ternary data were fitted on the basis of an extended Redlich–Kister–Muggianu model for substitutional solutions. Additionally, a comparison of these results to the extrapolation model of Toop is given. The entire ternary system shows exothermic values of Δ(mix)H ranging from approx. −1300 J/mol, the minimum in the Sb–Sn binary system down to approx. −24,500 J/mol towards Ni–Sb. No significant ternary interaction could be deduced from our data.