Influence of silver on electrochemical and corrosion behaviours of Pb-Ca-Sn-Al grid alloys. II. A.c. impedance and scanning electron microscopy studies

摘要

The influence of silver, in the range of 0.02 to 0.07 wt %, on the electrochemical and corrosion properties of Pb-Ca-Sn-Al grid alloy in sulfuric acid solutions at room temperature was investigated by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). EIS was used to study the effect of silver on the surface layer(s) of an electrode under different conditions, while the oxide layers produced on the working electrode surface were examined by SEM. The addition of silver in the alloy inhibits the reactions of Pb to PbSO sub 4 and PbSO sub 4 to PbO sub 2 and produces a more dense oxide layer which could enhance the corrosion resistance of the alloy.