Microstructure and Corrosion Resistance of Composite nc-TiO2/Ni Coating on 316L Steel

The aim of this work was to obtain composite of nc-TiO2/Ni coatings on 316L steel and to characterize their corrosion resistance. In order to investigate the influence of the addition of TiO2 nanoparticles, both pure Ni and composite nc-TiO2/Ni coatings were electrodeposited from nickel citrate baths. The microstructure of the coatings was examined by scanning and transmission electron microscopy. The nc-TiO2/Ni coatings were about 10 μm thick. Their microstructure consisted of TiO2 nanoparticles uniformly distributed in nanocrystalline Ni matrix. The corrosion resistance of the coatings was measured using impedance spectroscopy and polarization curves techniques in Ringer’s solution. It was determined that the addition of nano-TiO2 particles improved corrosion resistance and reduced corrosion rate of the coated steel

Preparation and characterization of Ni-TiO2 nanocomposite coatings produced by electrodeposition technique

In this paper Ni-TiO2 nanocomposite coatings with different sizes of TiO2 nanoparticles were successfully prepared by electrodeposition process from a nickel electrolyte in which the TiO2 nanoparticles were suspended. The influence of relevant deposition parameters on the nanocomposite coating characteristics was discussed. X-ray diffractometer (XRD) has been applied in order to investigate the phase structure of the nanocomposite coatings. The surface morphology of nanocomposite coatings was characterized by a scanning electron microscopy equipped with an energy dispersive spectroscopy (SEM/EDS). The electrodeposited nanocomposite coatings obtained at different deposition parameters were evaluated for their mechanical and corrosive properties. Obtained results show that the size of TiO2 nanoparticles and applied current density during deposition process has a direct effect on mechanical and corrosive properties of nanocomposite coatings. Increasing current density and smaller nanoparticle size has affirmative effect on mechanical properties whereas corrosion resistance of nanocomposite coatings deposited at 3 A.dm-2 current density are higher than the coatings prepared at higher current density values