Electrochemical Corrosion Inhibition Of Al -Alloy In Phosphoric Acid

Abstract

Electrochemical corrosion inhibition of aluminum die casting alloy (A383) in H₃PO₄ has been studied using different electrochemical techniques. The results of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements confirm the inhibition effects of K₂CrO₄ which describe the increase in the effectiveness of a corrosion inhibitor in the presence of 0.1M K₂CrO₄ in 0.5 M H₃PO₄. The results indicated that both concentration and the immersion time affect the inhibition efficiency (IE%). Langmuir adsorption isotherm was found to fit well with the experimental data.  The obtained results were confirmed by surface examination using scanning electron microscope.

Keywords: A383, Polarization, EIS, SEM, Acid inhibition.