Effect of Strain Rate and Temperature on the Tensile Properties of Tin-Based Lead-Free Solder Alloys

The tensile properties of Sn-3Ag-0.5Cu, Sn-3.5Ag, and Sn-0.7Cu lead-free solders were investigated on small-scale specimens and compared with those of Sn-37Pb eutectic solder at various strain rates from 1 × 10−4 s−1 to 1 × 10−2 s−1 and over a wide temperature range from 25°C to 150°C. The tests were under true strain-rate-controlled conditions. The ductility of each lead-free solder is relatively constant while that for Sn-Pb eutectic solder strongly depends on strain rate and temperature. The strain rate sensitivity index m for lead-free solders is relatively stable and showed little dependence on temperature, whereas the values of m for Sn-37Pb increased linearly with increasing temperature.