Inhibition of corrosion of aluminium in an aqueous solution at pH 11 by succinic acid-Zn2+ system

P. Satyabama, S. Rajendran and

Abstract

The inhibition efficiency of succinic acid in contr olling corrosion of Aluminium in an aqueous solutio n at pH 11, in the absence and presence of Zn 2+ has been evaluated by weight loss method. The form ulation consisting of 250 ppm of succinic acid and 50 ppm of Zn 2+ has 95% corrosion inhibition efficiency. A synergi stic effect exits between succinic acid and Zn 2+ . The mechanistic aspects of corrosion inhibition h ave been evaluated by polarization study and AC impedance spectra. In the presence of inhibi tor , linear polarization resistance increases ;cor rosion current decreases; charge transfer resistance value increas es; impedance value increases and double large capa citance decreases . The protective film has been analyzed b y SEM and EDAX.