In situ composite coating of titania–hydroxyapatite on titanium substrate by micro-arc oxidation coupled with electrophoretic deposition processing

• HA/TiO 2 coating were prepared by a MAO&EPD technique. • The NaOH electrolyte solution containing HA particles is employed. • MAO&EPD treatment enhances the corrosion resistance and bioactivity of titanium. In situ composite coating of hydroxyapatite (HA)/TiO 2 were produced on titanium (Ti) substrate by micro-arc oxidation coupled with electrophoretic deposition (MAO&EPD) technique with different concentrations of HA particles in the 0.2 M NaOH electrolyte solution. The surface morphology and chemical composition of the hybrid coating were effected by HA concentration. The amount of HA particles incorporated into coating layer increased with increasing HA concentration used in the electrolyte solution. The corrosion behavior of the coating layer in simulated body fluids (SBF) was evaluated using a potentiodynamic polarization test. The corrosion resistance of the coated sample was increased compared to the untreated Ti sample. The in vitro bioactivity assessment showed that the MAO&EPD treated Ti substrate possessed higher apatite-forming ability than the untreated Ti. Moreover, the apatite-forming ability had a positive correlation with HA concentration. In addition, the cell behavior was also examined using cell proliferation assay and alkaline phosphatase ability. The coating formed at HA concentration of 5 g/L exhibited the highest cell ability.