화학공학소재연구정보센터
Indian Journal of Chemical Technology, Vol.16, No.3, 216-220, 2009
Characterization of corrosion resistance properties of sol-gel alumina coating in mine water environment
Sol-gel alumina coating was developed on mild steel surface by using dip coating technique. Prior to the sol-gel coating, the substrate was treated with zinc-phosphating solution to improve the bonding of the coating. The corrosion resistance properties of the sol-gel alumina coated, uncoated and surface pre-treated substrates were evaluated in an artificial mine water solution. Electrochemical measurements like OCP variation with time, partial polarisation and electrochemical impedance analysis were carried out to evaluate corrosion resistance properties of the coatings. The microstructure and compositional analysis of the sol-gel coated specimens were investigated by SEM and XRD, respectively. The experimental results exhibited a significant improvement in the corrosion resistance of the sol-gel coated specimens as compared to the uncoated and surface pre-treated specimens. The SEM micrographs showed the presence of a compact coating of thickness 20 micron (approx). The XRD spectrum of the sol-gel coated specimens suggested the presence of alpha-alumina phase in the coating.