Electrochemical behavior of zirconia based coatings on mild steel prepared by sol-gel method

Abstract

Sol–gel zirconia, yttria stabilized zirconia (YSZ) and alumina stabilized zirconia (AlSZ) coatings were deposited on mild steel to improve its corrosion resistance properties. A suitable conversion coating, prior to the sol–gel zirconia based coating was applied to minimize the interference of non-protective rust. X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR) and scanning electron microscopy (SEM) were used to characterize the coatings. The electrochemical corrosion behavior of the coatings was evaluated in 3.5 wt.% NaCl by potentiodynamic polarization and electrochemical impedance techniques. The sol–gel coatings exhibited barrier type protection of the substrate.