Evaluation of the microstructure, thermal, and mechanical characteristics of Sn-9Zn reinforced with Ni and ZrO₂ nanoparticles via vacuum melting process

Abstract

The impact of minor additions of nickel and ZrO2 nanoparticles to eutectic Sn-9wt%Zn (SZ) 
prepared by vacuum melting technique was investigated. The morphologies and microstructures 
were carried out using an optical microscope (OM) and field emission scanning electron 
microscope technique (FESEM) escorted by energy dispersive x-ray spectrometry (EDX). The 
phase structure of the specimens was confirmed by an X-ray diffractometer (XRD). The results 
obtained demonstrate that small Ni addition causes a major grain refinement of β-Sn, due to the 
formation of the fine intermetallic compounds Ni5Zn21 and Sn3Ni4Zn3 phases and refines the 
formation of α- Zn lamellar phase. The melting temperature of the recently discovered solder alloys 
was lower than that of the eutectic Sn-Zn solders (∆Tm ~ 28 ºC) as a result of the preparation 
technique and the incorporation of Ni and ZrO2 nanoparticles. The tensile test showed enhanced 
the mechanical properties of SZ solder as a result of the addition of third elements. The 
experimental results showed that of all the alloys under investigation, the SZN903 alloy had the 
greatest UTS and YS values. The enhanced strength of the SZ-ZrO2 alloy defended the results of 
σUTS and increased the stress exponent parameters, n, by ∼20%. All solders had an activation 
energy Q that measured between ∼35.62 kJ/mol to ∼58.12 kJ/mol which comparable to the pipe-diffusion mechanism.