Study of corrosion inhibition of coupled Al2Cu-Al and Al3Fe-Al by cerium cinnamate using scanning vibrating electrode technique and scanning ion-selective electrode technique

The galvanic corrosion of the coupled Al2Cu and Al as well as Al3Fe and Al in 0.005 M NaCl in and without the presence of cerium cinnamate was studied. Scanning vibrating electrode technique and scanning ion-selective electrode technique were used to measure the distribution of current densities and pH. The results indicate that cerium cinnamate played inhibiting effect on the coupling corrosion of Al2Cu-Al and Al3Fe-Al. For Al2Cu-Al, the inhibition was mainly influenced by the production of cerium oxide/hydroxide on Al2Cu surface. However, for Al3Fe-Al, the inhibition was mainly influenced by the adsorbed cerium cinnamate on the Al3Fe surface.