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(Ni)/x(Sn) = 1:3. x(Ni)/x(Sn) = 1:4, and x(Ni)/x(Sb) = 1.4 at 1000 degrees 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 Delta H-mix 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.