from the conferences organized by TANGER Ltd. provisional website
Recently, as an alternative to the adhesive phosphate layers deposited on steel nanoscale adhesive coatings obtained from solutions hexafluorotitanic and hexafluorozirconic acids found their application worldwide. This paper is devoted to the development of technology of these coatings.A process of applying titanium oxide and zirconium oxide nano-coating on a steel base, which satisfy the requirements of the adhesive layers under the paintwork. The solution contains: 1.2 g / l H2TiF6; 0,02-0,16 g / l Ni2+, 1-3 g/l (NH4)2MoO4. It is found that the allowable value of the solution pH in the range 4.5-5.5 units. By means of X-ray photoelectron spectroscopy (XPS) the chemical composition of coatings was defined and we assume that the protective film includes TiO2 (ZrO2), FeO and Fe2O3 mainly.The effect of temperature of the solution to the properties of coatings showed that its heating up to 40° C does not affect the appearance and the protective ability of the coating.It is stated that the thickness of the coating increases during the first three minutes, and stabilized at values of 50-60 nm for titanium oxide coatings and 60-70 nm for zirconium oxide coatings.The morphology of coatings was examined by atomic force microscopy (AFM). It was found that the crystallite size is up to 300 nm, and the surface is quite homogeneous.Corrosion tests have shown that obtained ceramic nanocoatings have protective ability which corresponds the requirements for the adhesive layers under the paint coatings. These coatings have protective characteristics which are highly competitive with silicone and amorphous phosphate coatings and are similar to the protective characteristics of crystalline phosphate coatings.Keywords: Corrosion protection, conversion coatings, zirconium-oxide coatings, titanium-oxide coatings, surface treatment
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