Effect of bismuth and silver on the corrosion behavior of Sn–9Zn alloy in NaCl 3 wt.% solution

The effect of silver (Ag) and bismuth (Bi) on the corrosion resistance of Sn–9Zn alloy in NaCl 3 wt.% solution was investigated using electrochemical techniques. The results showed that the addition of Bi and Ag lead to the increase of corrosion rate and the corrosion potential Ecorr is shifted towards less noble values. After immersion, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive of spectroscopy (EDS) analysis of the corroded alloy surface revealed the nature of corrosion products. EDS and XRD analyses confirmed the oxide of zinc (ZnO and Zn5(OH)8Cl2H2O) as the major corrosion product formed on the outer surface of in the tested three solder alloys.