Microstructure Characterization of Titania-Based Micro-Arc Oxidation Coatings with Nanoparticles

Micro-arc oxidation (MAO) has proven to be a very promising method for the fabrication of functional coatings on titanium-based materials intended for dental implant application. The possibility of mixing the electrolyte components and/or adding the nanopowder opened a way to produce antibacterial surfaces. In the present work, the microstructure study of MAO coatings was carried out with the use of cutting-edge electron microscopes to reveal the way of the incorporation of the metallic and ceramic nanoparticles. These studies showed the possibility of the incorporation of metallic and ceramic nanoparticles into the MAO coating both from the as-supplied nanopowder and from the mix of inorganic salts. The produced nanoparticles locate preferentially on the very top of the coating and areas close to porosity. Furthermore, the use of silver acetate allows the production of ultrafine nanoparticles (with a size <10 nm), unachievable for as-supplied nanopowder.