Investigation of Akuamma Seed Extract on Corrosion Inhibition of Aluminum in Hydrochloric Acid Pickling Environment

Abstract

Inhibitive impact of Akuamma seed (AS) extract toward 1.0M HCl corrosion of aluminum was examined using response surface methodology (RSM). Gravimetric (weight loss), potentiodynamic polarization and electrochemical impedance spectroscopy techniques were used in the corrosion inhibition process. In all the method used, the seed extract acted as good corrosion inhibitor of aluminum in 1.0M HCl solution. Optimal inhibition efficiency of 72.6% was obtained at optimum inhibition concentration of 1.2g/l, temperature of 304.19k and maximized time of 11.53hrs. It showed that the plant extract has excellent inhibitive properties for the corrosion inhibition process. The values of k_ads are relatively small indicating that the interaction between the adsorbed extract molecules and aluminum surface is a physical process. The (AS) extract protects aluminum against pitting corrosion. The level of protection increases with increase extract concentrations. The extract inhibited both cathodic and anodic reactions and acted as mixed-type inhibitor.