Síntesis y evaluación de resistencia a la corrosión de recubrimientos de SiO2-TiO2-ZrO2-BiO2 sobre acero inoxidable 316L producidos por sol-gel

This report show the synthesis and corrosion resistance of SiO2-TiO2-ZrO2-BiO2 coatings deposited by spin-coating on AISI 316L stainless steel. The soles were prepared from a mixture of organic precursors, such as 98% tetraethoxysilane (TEOS), titanium tetrabutoxide (TBT) 97%, Zirconium (IV) butoxide (TBZ) 80% in 1-butanol solution and bismuth penta nitrate-hydrate Bi (NO3)3*5H2O. The coatings were evaluated by potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS) test in an electrolytic solution of 3.5% Wt NaCl + 0.5 M H2SO4. The soles prepared were studied trough rheological, pH as a time function, Fourier Transform Infrared Spectroscopy (FTIR) and differential scanning calorimetry (DSC) analysis. The coating were characterized by X ray diffraction (XRD), scanning electron microscopy (SEM) and dispersive energy spectroscopy (EDX), X ray fluorescence (XRF) and adhesion measurements. The results showed that the films offer good corrosion resistance on the metal substrate, decreasing current densities up to one order of magnitude.