Characterization of Mechanical Properties of Eutectic Sn-Co-Cu Lead Free Alloy

The Sn-Co-Cu eutectic solder alloy is a less expensive and is therefore a possible alternative to the Sn-Ag-Cu alloys. The Sn-Co-Cu system eutectic composition was obtained by means of CALPHAD (calculation of phase diagram) methodology. The composition of the Sn-rich, eutectic Sn-Co-Cu system was found to be 0.4%Co and 0.7%Cu (wt%) with a melting point of 224degC The tensile behavior of the eutectic Sn-0.4Co-0.7Cu bulk samples was studied under three different conditions of strain rates (10^-6, 10^-4 and 10^-3/s) and compared to both Sn-37Pb and Sn-4.0Ag-0.5Cu alloys. The evaluation of the tensile results showed that the effect of strain rate played an important roll on the tensile properties of these alloys, and it is clearly observed that the tensile strength increases as the strain rate increases. Furthermore, Sn-4.0Ag-0.5Cu alloy shows better ultimate tensile strength (UTS) followed by Sn-37P and Sn-0.4Co-0.7Cu system