Electrochemical characteristics of Pb–Sb alloys in sulfuric acid solutions

Lead–antimony alloys with a wide range of Sb contents, pure Pb and pure Sb were subjected to sulfuric acid solutions to elucidate their electrochemical characteristics by cyclic voltammetry and corrosion potential measurements. A corrosion test with a Pb/Sb galvanic couple was also done. For Pb-rich α-phase alloys (<0.3 wt.% Sb), their electrochemical behavior was similar to that of pure Pb. On the other hand, for α+β phase alloys (>0.3 wt.% Sb) their behavior was quite different from those of α-phase alloys; (i) dissolution current of Sb was proportional to Sb contents; (ii) hydrogen overvoltage was decreased remarkably with increasing the Sb contents; (iii) the corrosion potential shifted and approached that of pure Sb with time. It is confirmed that the electrochemical behavior of Pb–Sb alloys is related to the electrochemical property of the individual phase involved in the internal galvanic couples formed.