Pb-free solders: Surface tension calculation of the Ag-Bi-Sn ternary alloys at 873 k

Surface tensions of the ag-bi-sn ternary system alloys are calculated from the surface tensions of the ag-bi,ag-sn and bi-sn sub-binary systems by using geometric models (kohler,toop and hillert). at the same time,the surface tension of the ag-bi-sn ternary alloys at 873k and their sub-binary systems are predicted on the basis of butler's equation in combination with thermodynamic data. except for the asymmetric toop and hillert models,the agreement between the calculated results and experimental data is quite good using kohler and butler's models. with increasing amount of bismuth the surface tension decreases slightly. the rich-silver cross-section shows that silver has no appreciable effect on increasing the surface tension.