Mechanical deformation behavior and mechanism of Sn-58Bi solder alloys under different temperatures and strain rates

The mechanical deformation characteristics of the eutectic Sn-Bi alloys were investigated by tensile tests combined with in-situ observation and nanoindentation. The effects of temperature and strain rate on mechanical deformation behavior were investigated. Tensile tests reveal that the increasing of temperature improves the ductility of the alloys. However, the ductility significantly deteriorated at high strain rate. The nanoindentation results show that there exist different deformation mechanisms applying different strain rates. The deformability of the alloy decreased at high stain rate because of the mechanism transformation form phase boundary related mechanism to dislocation glide mechanism. This impact of strain rate on the deformability appears weaker due to the enhancement of the interface sliding at high temperature.