Journal of Materials Science, Vol.45, No.24, 6812-6818, 2010
Cu(II), Co(II) and Ni(II) complexes of -Br and -OCH2CH3 substituted Schiff bases as corrosion inhibitors for aluminium in acidic media
A group of Cu(II), Ni(II) and Co(II) complexes of -Br and -OCH2CH3 substituted Schiff bases as a new class of corrosion inhibitors for aluminium has been studied in 0.1 MHCl by the addition of 10 ppm compound using potentiodynamic polarization, electrochemical impedance spectroscopy, linear polarization methods and gas evolution tests at 25 degrees C. The inhibition efficiencies obtained from all methods employed are in good agreement. Results show Ni(II) complex of -OCH2CH3 substituted Schiff bases was the best inhibitor with a mean efficiency of 69% at 10 ppm additive concentration. The potentiodynamic polarization curves showed both the cathodic and the anodic processes of aluminium corrosion were suppressed, and the Nyquist plots of impedance gave mainly a capacitive loop. Scanning electron microscopy (SEM) was done from the surface of the exposed sample indicating uniform film on the surface.