Oxidation resistance of mild steel by zirconia sol–gel coatings

The effect of zirconia coatings deposited by the Sol–gel technique on the oxidation of mild steel was studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and measuring the weight gain. It was found that the thickness of zirconia coatings is a crucial factor affecting the oxidation kinetics and that a multi-layer coating is much more effective than the single-layer one. Auger electron spectroscopy (AES) was used to evaluate the depth composition of the coatings. The results suggest that the zirconia coatings deposited on mild steel just retard the oxidation, but do not suppress the oxidation.