Effect of intermetallic compounds on the activation of aluminium anodes

The electrochemical characterization of aluminium anodes containing different intermetallic compounds in 3% sodium chloride and 0.3% sodium sulphate aqueous solutions was carried out by means of d.c. measurements. The case of some Ca-Zn, Ca-In and Al-Mg-Zn intermetallic compounds in the aluminium matrix was examined. SEM and EDAX analyses were used to examine the surface structure of the anodic materials. The relationship between morphological structure and electrochemical results was studied and particular attention was paid to the influence of the intermetallic phases on the activation of aluminium anode materials. Different heat treatments, performed to ensure the dispersion of the fine intermetallic phases, were adopted and the results are briefly discussed.