Effect of Allium Sativum Extracts on the Corrosion and Inhibition of α- Brass in HCl

Abstract

An investigation of the effect of allium sativum (garlic) extract as a ‘green’ inhibitor on the corrosion and inhibition of α-brass in 0.5M HCl was performed at ambient temperature. Weight loss and corrosion rate and potentiodynamic polarization measurement techniques were used for the experimental work. Potentiodynamic polarization measurement was performed using a potentiostat (Autolab PGSTAT 30 ECO CHIMIE) interfaced with a computer for data acquisition and analysis. This work reports the gravimetric and electrochemical response of the study. The obtained results showed effective corrosion inhibition of the garlic extract on the test-specimens in the different concentrations of the test medium. Though there was inconsistent increasing inhibition performance with increasing concentration of inhibitor, the overall performance was not effective at other concentrations other than the 100%’s. The only appreciable corrosion inhibition performance was achieved with the 100% (as extracted) garlic concentration. In 0.5M HCl, and as at 360 hours (15 days) of the experiment, 100% garlic gave the optimal performance with weight loss of -0.020g, polarization resistance value of 6.88E+03 Ω, corrosion rate, CR, of 3.44E – 02 mm/yr and current density (Icorr) value of 3.74E-06 A/cm 2 . A mixed type inhibitor was indicated by the results of ba and bc.