Influence of the Micro-Arc Oxidation (MAO) Parameters on Surface Properties of the Hydroxyapatite and Hydroxyapatite - Carbon Nanotube Coatings Formed on the Ti13Nb13Zr Alloy

MAO processing of titanium biomaterials for long-term implants forms oxide layers resistant to mechanical stresses during surgery, making them among the best surface modifications. Bioactivity can be enhanced using electrolytes with calcium, phosphate, or apatite; mechanical and corrosion properties can be improved by adding other compounds. This study examines effects of voltage, current, deposition time, hydroxyapatite (HA) and multi-walled carbon nanotubes (MWCNTs) in the electrolyte on Ti13Nb13Zr alloy surface properties. Methods included SEM, EDS, profilometry, hardness, corrosion, and wettability tests. CNTs improved mechanical properties, reduced corrosion resistance, slightly affected wettability. Voltage controlled plasma oxidation intensity; current affected ion/molecule mass flux.