Surface tension and density of liquid Bi-Pb, Bi-Sn and Bi-Pb-Sn eutectic alloys

► Surface tension is of great importance for all casting and joining processes. ► Bi-Sn alloys are good alternative lead-free solder materials. ► Bi57Sn43 and Bi46Pb29Sn25 are model materials for the steel casting processes. ► Pb and Bi-Pb eutectic alloy are used as coolants for new generation of reactors. ► Calculation of the surface tension of alloy melts by the Butler model. ► Prediction of the surface tension can compensate the lack of experimental data.