Electrosynthesis and performances of cobalt–ceria nanocomposite biocoatings
Résumé
Co–CeO2 nanocomposite coatings were obtained by electrocodeposition of nanoparticulate cerium oxide bioceramic (25 nm mean diameter) into cobalt matrix on stainless steel support and the resulting properties were evaluated comparatively with pure cobalt layers. The surface and anticorrosion properties in the simulating body fluid (SBF) solution of the obtained Co–CeO2 nanocomposite layers are characterised using scanning electron microscopy with energy dispersive spectroscopy system, ultrahigh microtopography, Vickers surface microhardness, linear polarisation and electrochemical impedance spectroscopy techniques. The results indicate that CeO2 nanoparticles are uniformly dispersed into cobalt matrix and influence the surface morphology, microtopography, and microhardness and corrosion behaviour of nanocomposite coatings obtained. Coating thickness increases with increased current density as well as the surface roughness and microhardness. At the same time, the results obtained by corrosion tests show that when compared with the traditional polycrystalline cobalt films, the obtained Co–CeO2 nanocomposite layers exhibit the enhanced corrosion resistance in the SBF solution.