Micro-arc oxidation treatment to improve the hard-tissue compatibility of Ti-29Nb-13Ta-4.6Zr alloy

► Thick and porous oxide layer was formed on Ti alloy with micro-arc oxidation treatment. ► Ca, P, and Mg from the electrolyte were incorporated in the resultant oxide layer. ► Calcium phosphate formation was much accelerated on the treated sample. ► Micro-arc oxidation enhances the bioactivity of the biocompatible Ti alloy.