Effect of nano-TiO2 particles and cooling rate on the thermal, microstructure and mechanical properties of novel low-ag Sn1.5Sb1Ag solders

The effects of added nano-TiO2 and cooling rate on the thermal, microstructural, and mechanical properties of low-Ag Sn1.5Sb1Ag (SSA) composite solders have been investigated. Adding nano-TiO2 into the low-Ag SSA solder increases the melting temperature by only 2.7-2.8 °C. It was also confirmed that the combination of a fast cooling rate (FC) and nano-TiO2 particles affects the microstructural and mechanical properties. The UTS, 0.2YS, and microhardness of the FC-SSA composite solder improved, which could be attributed to the refinement of the β-Sn(Sb) grain size, the precipitation of ε-Ag3(Sn,Sb), and the second phase dispersion strengthening mechanism. The fracture mechanism of SSA composite solders was confirmed to be the ductile fracture mode.