Characteristics of Zn–Sb based high temperature solder alloy

Abstract

In this study, the newly developed Zn based solder alloys with different amount of Sb doping (i.e. Zn–1.2 wt% Sb, Zn–1.7 wt% Sb and Zn–2.2 wt% Sb) were investigated for microstructural, thermal, mechanical and electrical properties. The microstructure of Pb-free eutectic Zn–1.7 wt% Sb alloy was found finer lamellar structure and observed better properties than the other two alloys. The pro-eutectic Zn–1.2 wt% Sb exhibited comparatively coarser structure and resulted lower mechanical as well as electrical properties. The formation of the Zn4Sb3 intermetallic phases were identified and also quantified by X-ray diffraction analysis. The presence of higher amount of intermetallic compounds in hypereutectic Zn–2.2 wt% Sb systems deteriorated the tensile properties of the binary alloy. The melting behavior of the solder alloys studied by differential scanning calorimetry analysis revealed that the melting temperature range of the solder alloys were quite close with the Sb addition concerned. In this study, creep behavior of the lead-free Zn–xSb solder alloys were studied by long-time Vickers indentation testing at room temperature. The eutectic Zn–1.7 wt% Sb exhibited lowest creep strain over the other two alloys.