Microstructure, hardness, electrical, and thermal conductivity of SZCN solder reinforced with TiO2 and ZrO2 nanoparticles fabricated by powder metallurgy method

Abstract

Abstract The microstructure and characterization of Sn–Zn–Cu–Ni (SZCN) solder alloy reinforced with TiO 2 and ZrO 2 nanoparticles (NPs) synthesized by powder metallurgy were investigated. Sn, Zn, Cu and Ni metallic powders were mixed mechanical by 10:1 ball to powder ratio with 300 rpm speed for 2 h. Then 0.5 wt% from nano ZrO 2 or TiO 2 was mixed by the same parameters with the mixed metal powder. The morphologies and microstructures development during the fabrication process was investigated by X-ray diffractometer (XRD), optical microscope (OM), and scanning electron microscope (SEM) with energy dispersive X-ray spectrometry (EDX). The results reveal an improved distribution of TiO 2 or ZrO 2 NPs in the SZCN matrix solder, which resulted in an improvement in its density. The analyses of microstructural demonstrated that the addition of TiO 2 or ZrO 2 NPs to SZCN solder results in the grain refinement of the β-Sn phase, besides the formation of Ni 3 Sn IMC with small size and uniform distribution. The microhardness was enhanced as a result of the addition of TiO 2 or ZrO 2 NPs. The experimental results showed that the SZCN-ZrO 2 composite solder had the greatest hardness and stress exponent values due to its effectiveness in suppressing the growth of β-Sn grains and the pile-up of dislocations. Both the electrical and thermal conductivities were improved by incorporating TiO 2 NPs compared to other solders.