Review of the Effect of Presence of Yttria and Benzotriazole Inhibitor Factor on Electrochemical Properties and Activation of Self-Healing Mechanism in Alumina-Based Coatings

In this study, the effect of yttria and benzotriazole doping on corrosion behavior and activation of self-healing mechanism in Alumina-based nanostructured coatings was investigated. Single-component Alumina, double-component Alumina-Ytteria, and triple-component Alumina-Ytteria-benzotriazole ceramic-based coatings have been ‎layer-deposited over St52 steel surface by the sol-gel process in order to improve the abrasion and corrosion behaviour of this steel. Afterwards, phase analysis, morphology, and topography of these coatings have ‎been carried ‎out respectively by Grazing Incidence X-ray Diffraction (GIXRD), Field Emission Scanning ‎‎Electron Microscopy (FE-SEM), and Atomic Force Microscopy (AFM).‎ Moreover, in order to investigate ‎elemental distribution in layer-deposited coatings, Energy ‎Dispersive Spectroscopy (EDS) ‎was performed.‎ Also, the corrosion behaviour of under-investigation coatings ‎and substrate were studied using electrochemical impedance spectroscopy and potentiodynamic ‎polarization for 1, 48, and 96 hours of immersion in 3.5wt%NaCl solution. GIXRD results revealed the ‎amorphous nature of the coatings and the absence of formation of ‎crystalline structure. AFM and FE-SEM ‎observations revealed intactness of double-component Alumina-Ytteria and Alumina-Ytteria-benzotriazole ‎coatings in comparison with single component Aluminacoating.