Analysis of corrosion behavior and its characterization of in-sn-bi alloy

Abstract

This work is focused to investigate the corrosion behaviour of lead free solder alloys using potentiodynamic polarization test. Investigation was carried out in simulated sea water comprising 3.5 wt % NaCl solution of five different compositions in (Sn0.33Bi0.67)1-x Inx system. Indium content was kept varying along 0.1, 0.3, 0.5, 0.7 and 0.9 in five different alloys. Results were analysed in combination with EDX and XRD of corrosion product. Analysis indicates strong influence of indium on corrosion resistance in In-Sn-Bi alloys. Indium decreases the corrosion resistance of these alloys by forming In(OH)3 in corrosion product. The electrolyte penetrates through corrosion product, which is not impervious on the surface. This might be happened because of the formation of In(OH)3 in the corrosion product which is loosely bonded on the surface and it allows further corrosion which can be seen in SEM micrograph of corrosion product. © 2019 Elsevier Ltd.