Mechanical and corrosion-resistance performance of electrodepo sited titania-nickel nanocomposite coatings

Titania-nickel nanocomposite coatings consisting of a nanocrystalline nickel matrix (average grain size: 10 nm) and nanometer-sized titania particles dispersed in the nickel matrix on copper substrates were prepared by simultaneous electrodeposition of nickel and titania from a nickel electrolyte in which the titania particles were suspended. The nanocomposite coatings were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Vickers microhardness tests, and corrosion tests. The results indicate that the concentration of the titania particles in electrolytes affects the content of titania in the composite coatings. Vickers microhardness and corrosion resistance of the nanocomposite coatings increase with increasing content or decreasing grain size of titania particles in the composite coatings. The nanocomposite coatings containing anatase nanoparticles have a higher hardness and lower corrosion rate compared with those containing rutile microparticles. (C) 2004 Elsevier B.V. All rights reserved.