Effects of fullerenes reinforcement on the performance of 96.5Sn–3Ag–0.5Cu lead-free solder

In this study, fullerenes (FNSs) nanoparticles with different weight fractions (0.05, 0.1 and 0.2 wt%) were successfully integrated into SAC305 lead-free solder utilizing a powder metallurgy route. The composite solders were then studied extensively concerning their microstructures, wettability, thermal and mechanical properties. Refined microstructures were observed in the matrices of the composite solders after the addition of FNSs nanoparticles to the solder alloy. With an increase in the amount of FNSs nanoparticles added, the composite solders exhibited a homologous improvement in wettability. Furthermore, the electrical resistance and melting point of the solder changed only marginally after the addition of the FNSs nanoparticles. According to the mechanical results, the 0.2 wt% FNSs addition would give rise to a 12.1% and 19.9% improvement in shear strength and microhardness respectively in comparison to the unreinforced solders. These progressions can be attributed to the refined microstructures and the presence of uniformly dispersed FNSs nanoparticles, which acted as reinforcements. Finally, the existence of added FNSs nanoparticles in the solder matrix was further confirmed by energy-dispersive X-ray spectroscopy, scanning electron microscopy, and Raman spectroscopy.