Electrodeposited Zn–TiO2 nanocomposite coatings and their corrosion behavior

Abstract

The present paper aims to investigate the electrodeposition on steel substrate and the corrosion behavior of Zn-TiO 2 nanocomposite coatings. Zn-TiO 2 composite coatings were electrodeposited on OL 37 steel from an electrolyte containing ZnCl 2 , KCl, HBO 3 (pH 5.7) brightening agents and dispersed nanosized TiO 2 . Corrosion measurements were performed in 0.2 g L -1 (NH 4 ) 2 SO 4 solution (pH 3) by using electrochemical methods (open-circuit potential measurements, polarization curves, electrochemical impedance spectroscopy). The results of electrochemical measurements were corroborated with those obtained by using non-electrochemical methods (X-ray diffraction, atomic force microscopy and scanning electron microscopy). The results indicate that the composite coatings exhibit higher corrosion resistance as compared to pure Zn coatings and a non-linear dependence of their polarization resistance on TiO 2 concentration in the plating bath was found. The importance of TiO 2 nature and concentration regarding the properties of the composite coatings was demonstrated.

Effect of ethyl vanillin on ZnNi alloy electrodeposition and its properties

“…The higher R P value was due to both charge transfer resistance and increase in the thickness of the corrosion product layer. The decrease in double layer capacitance resulted from a reduction in the local dielectric constant and/or from increased double layer thickness (Vlasa et al 2010).…”

Optimization of zinc‐nickel film electrodeposition for better corrosion resistant characteristics

“…After 24 h of immersion time, the corrosion resistance of the plated sample continuously decreases, as shown in Figure 14. Feng et al, [44,45] Gomes et al, [46] and Vlasa et al [53] have reported similar results.…”

Controlled adsorption of titanium(IV) oxide particles on electroplated zinc coatings to improve the corrosion resistance of chromium(VI)‐free conversion layers

“…Presently, a strong emphasis on the development of advanced functional and smart coatings for corrosion protection in different technological applications is observable [3]. One approach to increase wear and corrosion protection of conventional applications is the incorporation of hard particles in zinc coatings by electrodeposition with hexavalent chromium free passivation layers [4][5][6][7], which would reduce problems related to crack and hole formation in such coatings. However, in electrolytes submicron particles tend to significantly agglomerate due to strong electrostatic particle-particle interactions as a result of the high electrical conductivity of electrolytes.…”