Development of aluminium alloy anodes for cathodic protection of ships

WITH A VIEW to developing aluminium alloy hanging anodes and high efficiency aluminium alloy sacrificial anodes, different percentages of magnesium and bismuth were added separately to (Al + 5%Zn + 0.03%ln), and electrochemical studies were carried out. The results show that the composition containing 0.4% bismuth exhibits minimum open-circuit potentials and hence it can be used as an hanging anode. It was also observed that the closed-circuit potentials were shifted to the anodic direction with increasing magnesium and bismuth contents, and the efficiency of the anode was inversely proportional to the percentages of magnesium and bismuth in the alloy anode.