Effect of heat treatment on corrosion properties of sol–gel titania–ceria nanocomposite coating

The objective of this work is to study the effect of heat treatment temperature on corrosion resistance of TiO2–CeO2 composite coatings deposited by sol–gel method. TiO2–CeO2 thin films were applied on 316L stainless steel substrates via spin coating technique. The samples were heat treated at different temperatures from 300 to 500 °C and the corrosion resistance of the coated samples was determined by dynamic polarization and electrochemical impedance spectroscopy (EIS) studies. Microstructures of the films were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analyses (EDX), X-ray diffraction (XRD), and differential thermal analysis (DTA). The results obtained from corrosion data showed that TiO2–CeO2 coating improves the corrosion resistance of 316L stainless steel substrate and higher pitting resistance achieved in comparison with the bare samples. On the other hand, corrosion current densities of the samples increased for more than three times as higher heat treatment temperatures were exploited.