Effect of Avogadro Oil as Corrosion Inhibitor of Thermally Pre-aged Al-Si-Mg Alloy in Sodium Chloride Solution

The corrosion inhibition of thermally pre-aged Aluminium-Silicon-Magnesium (Al-Si-Mg) alloy in 3.5 % NaCl solution with natural Avogadro oil of varying concentrations has been studied using linear polarization techniques. From the results obtained, the corrosion rate decreased with an increase in Avogadro oil concentration. An inhibitor efficiency of 46.7, 58 and 71 % were obtained at 1.5, 3.0, 4.5 g/v Avogadro oil addition in a 3.5 % NaCl solution respectively for the conventional alloy. Results from the linear polarization technique indicate a higher potential value with an increase in the polarization resistance (Rp) and lower current density in the inhibited samples than the uninhibited Al-Si-Mg alloy as obtained from the Tafel plot extrapolation. There exist some levels of correlation in the inhibitor efficiency between the conventional and the thermally pre-aged Al-Si-Mg alloy/Avogadro oil in 3.5 % NaCl solution