Microstructure characterization of titanium oxide coatings with nanoparticles deposited with micro-arc oxidation method on plastically deformed titanium

Antibacterial coatings produced on the surface of biomaterials have received considerable attention due to the possibility of protecting medical implants placed in the human body against bacterial colonization resulting in inflammation of the surrounding tissues. According to various sources, the percentage of all infections can reach up to 30% of all implanted materials, leading to serious consequences including the necessity of surgical intervention. Thus, a number of methods allowing the production of antibacterial coatings has been developed. Micro-arc oxidation, considered as a simple and environmentally friendly method of functional coating deposition on top of so-called “valve metals”, is gaining in importance in this field. The relative simplicity in the mixing of electrolyte constituents makes the incorporation of antibacterial elements possible.

In the present work, the coatings were produced by the micro-arc oxidation method on the surface of commercially pure titanium subjected to plastic deformation by means of hydrostatic extrusion. Metallic (Ag) and ceramic (ZrO₂/ ZnO/CeO2) types of antibacterial agents were applied. The substrate material presents strong substrate anisotropy, which strongly affects the microstructure and the functional properties of the produced coatings. Therefore, the use of advanced methods of scanning and transmission electron microscopy and X-ray photoelectron spectroscopy allowed us to optimize the parameters of the micro-arc oxidation process and reveal the mechanisms of the incorporation of antibacterial additions into the titanium oxide coating.

Acknowledgements

This research was conducted within the framework of a project funded by the National Science Center of Poland, under grant number UMO-2020/39/D/ST8/01783.