The influence of Lavandula angustifolia L. oil on corrosion of Al-3Mg alloy

► Lavandula angustifolia L . oil being a natural and environmentally benign product it can be used instead of toxic chemical inhibitors in preventing aluminium alloys from pitting corrosion. ► The increase of lavender oil concentration above a certain value has little effect on the surface coverage or inhibition efficiency. ► The lavender oil compounds adsorbed onto the metal surface follow the Langmuir adsorption isotherm. ► The values of Δ G ads 0 obtained support the mixed mode of adsorption (physisorption and chemisorption). Natural oil extracted from Lavandula angustifolia L. was investigated as corrosion inhibitor of Al-3 Mg alloy in 3% NaCl solution using weight loss, polarization measurements and SEM. The oil dissolved in ethanol and used as 30% (v/v) solution, was found to retard the corrosion rate of Al-3 Mg alloy even at high temperatures. The inhibiting effect of lavender oil components on Al-3 Mg surface was attributed to the Langmuir’s adsorption isotherm. It was found that the L. angustifolia L. oil provides a good protection to Al-3 Mg alloy against pitting corrosion in sodium chloride solution.