Calorimetric investigation of the Cu-Sn-Bi lead-free solder system

The thermodynamic properties play a crucial role in the development of new solder materials. In this work a calorimetric investigation of the ternary Cu-Sn-Bi system was carried out by using a Calvet-type calorimeter in order to obtain the molar limiting partial enthalpy of Cu in liquid Sn-Bi alloys with different compositions. The molar limiting partial enthalpy of Cu at 820 K was determined in the Sn-75 at% Bi, Sn-43 at% Bi and Sn-26 at% Bi liquid bath showing an endothermic behaviour. The results are compared with the literature data available for Cu in the pure liquid Bi and Sn and then discussed.