The effect of inhibitor on the corrosion of aluminum alloys in acidic solutions

The corrosion inhibition of Al and its alloys is the subject of tremendous technological importance due to the increased industrial applications of these materials. This study reports the results of weight loss, polarization and electrochemical impedance spectroscopic (EIS) measurements on the corrosion inhibition of AA6061 and AA6063 aluminum alloys in acidic solutions using sodium benzoate as an inhibitor. The results showed that addition of sodium benzoate retards the rate of dissolution and hence inhibits the corrosion of the aluminum alloy in acidic solutions. The inhibition efficiency increases with the increase of immersion time in acetic acid however it displays a different behavior in sulfuric acid. Electrochemical studies showed that there was a significant increase in overall resistance after addition of sodium benzoate, when compared to the case without inhibitor. Langmuir adsorption isotherm fits well with the experimental data.