Synthesis of bioactive ceramic on the titanium substrate by micro‐arc oxidation

Abstract Bioactive ceramic films on titanium substrate are prepared successfully by micro‐arc oxidation in electrolyte solution containing NaOH only. The coatings are prepared by micro‐arc oxidation at various applied current densities (200–400 mA/cm²) and in NaOH electrolyte with different concentrations. The XRD shows that they are composed of rutile, anatase, Na₂Ti₆O₁₃, and Na₂Ti₄O₉ phases. The composition and surface morphologies are strongly dependent on the applied current density and electrolyte concentration. For example, at high current density, the phase is mainly composed of rutile and Na₂Ti₆O₁₃, and at high electrolyte concentration, it is Na₂Ti₆O₁₃ phase. The morphologies of the samples vary with the increase of current and electrolyte concentration. The apatite‐inducing ability of bioactive ceramic films is evaluated in biological model fluids. After soaking in biological model fluids, the titania‐based coatings containing Na₂Ti₆O₁₃ phase have excellent capability of inducing bone‐like apatite. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009