Corrosion Resistance of Silane Films Modified with Yttrium Oxide Nanoparticles on AA6061-T6 Al Alloy Surface

The present work aims at evaluating the corrosion resistance of AA6061-T6 pre-treated with bis-1,2-triethoxysiylethane silane(BTSE) solution containing different contents of Y2O3 nanoparticles. The corrosion resistance of the pre-treated AA6061-T6 substrates was investigated with potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS) and neutral salt spray test (NSS). The morphology of silane film was observed using scanning electron microscopy (SEM). The results indicated that the presence of small amount of Y2O3 nanoparticles in BTSE solutions increased the corrosion resistance of the silane films in 3.5% NaCl solution. The formed silane film acts as a physical barrier for the protection of aluminum alloy. Y2O3 nanoparticles mainly inhibit the cathodic reduction reaction of electrochemical corrosion and do not change the dynamic behaviors of the electrode reaction of electrochemical corrosion. The scanning electron microscopy (SEM) images indicated that the surface morphology of silane films formed was flat and compact, when the contents of Y2O3 nanoparticles in BTSE solutions were between 10 mg/L and 20 mg/L.