Evaluation of Corrosion Inhibitors for Aluminum in Chloride Containing Solutions

Authors: Mübeccel ERGUN, Duygu BEKTAŞ

Abstract: Research has been conducted on the corrosion inhibition of commercial aluminum in aqueous solutions containing 100 ppm CL- ion alone or mixed with one of the following five inhibitors covering the concentration range of 1000-5000 ppm between pH 5 and 9: sodium chromate, sodium nitrite, sodium molybdate, sodium orthophosphate and sodium tetraborate. Compared with other inorganic inhibitors tested, chromate was found to be the most effective. The chromate was taken as a reference inhibitor against which the effectiveness of the binary and ternary inhibitor systems was compared. Comparison was made on the basis of inhibiton efficiency determined from the cathodic polarization data. Of all the inhibitor systems tried, sodium tetra borate-sodium chromate was found to be the most effective binary inhibitor blend, the effectivenes of which is equal that of sodium chromate alone in all ratios experienced.

Keywords: Corrosion Inhibition of Aluminum, Inhibitor Efficiency, Inhibitor Mixtures.