Corrosion inhibition of aluminum 2024-T3 in 3.5% NaCl by using litchi chinensis extract

The corrosion inhibition of AA2024-T3 Aluminium alloy in 3.5 % NaCl solution by using litchi chinensis seed ethanolic extract has been evaluated by using potentiodynamic polarization curves, linear polarization resistance and electrochemical impedance spectroscopy tests. Results have shown that the extract was a good corrosion inhibitor with an efficiency that increased with its concentration. Corrosion and passivation current density values were decreased indicating that the extract behaves as an anodic type of corrosion inhibitor. Inhibitor was adsorbed on to the metal surface in a combination of physical and chemical, dominated by a physical type of adsorption following a Langmuir adsorption isotherm. Corrosion rate was decreased due to the formation of a protective corrosion products layer which blocked further corrosion of metal by electrolyte.

Keywords: Aluminium, corrosion, sodium chloride, green inhibitor, litchi chinensis.