ACTIVATION OF ALUMINUM ANODES BY THE PRESENCE OF INTERMETALLIC COMPOUNDS

The electrochemical and corrosion behaviour of Al-Mg-Zn alloys in 3% s odium chloride and 0.3% sodium sulphate aqueous solution was studied, by means of dc and ac measurements at different polarization condition s. SEM and EDAX analysis were employed in order to characterize the su rface structure of the above alloys. The relationship between morpholo gical structure and electrochemical results was examined and particula r attention paid to the influence of the secondary phase. Different he at treatments, performed to ensure the dispersion of the fine intermet allic phases, were carried out and the results briefly discussed. (C) 1997 Elsevier Science Ltd.