Archives of Metallurgy and Materials

Abstract

Silicate coatings have been considered as an alternative to toxic and carcinogenic other chemical treatments. In this paper, a strengthened silicate coating was formed on the surface of low carbon steel by dip immersion method. The modification and strengthening was done by loading colloidal nano-SiO 2 into the film. The characterizations of nano-SiO 2 were investigated by FESEM, TEM and FT-IR. The effects of nano contents (weight ratio) and drying temperatures on corrosion properties of silicate film were studied. Potentiodynamic polarization, electrochemical impedance spectroscopy and immersion tests have been used to study corrosion behavior of nano-loaded silicate films. Surface morphology, microstructure and its chemical composition were analyzed by means of FESEM, EDS, AFM, XRD, GIXRD, ATR-FTIR and Raman techniques. Results indicated that colloidal nano-SiO 2 properly modified the silicate coatings and significantly improved the corrosion resistance and barrier property. Also drying temperature showed a considerable effect in silicate coating and higher corrosion resistance was obtained with 150°C curing.

Archives of Metallurgy and Materials

“…in this circuit, CPe dl was inserted instead of pure capacitor non-ideal behavior of electrochemical systems. The impedance of the CPe element is as follows [15]: 11) in this equation, Q represents the constant of the CPe, 1 j   , ω is the angular frequency and n is a factor that varies between 0 and 1 and indicates deviation from the ideal capacitor. The deviation of n away from unity can be attributed to the surface heterogeneity and roughness [9].…”

“…in order to homogenize the alloy surface and remove the loose oxide/hydroxide layer, the magnesium alloy was immersed in Cro 3 +hNo 3 solution before the electroless plating [8,9]. however, toxicity of the chromium compounds has persuaded the researchers to suggest several environmentally-friendly conversion coatings [10][11][12]. Despite the desirable results, the main drawback of these pretreatment layers is that the obtained nickel coating should be pore-free.…”