Calcium phosphate coating was made on the Ti-6Al-4V surface which was treated by micro-arc oxidation (MAO) by means of electrochemical deposition.Uniformity pores,which owned regular salience around pores,were formed on the Ti-6Al-4V,followed by deposited at different deposition time.Anode oxidation was used at 300V voltage for 1min.Electrochemical deposition was conducted at current densities of 25-30 mA/cm2 and 310K～315K for 10min and 60min,respectively.The surface morphology was observed by scanning electron microscopy(JSM-6360LV).The phases of coatings were analyzed by X-ray Diffraction(XRD).As the result,the coatings soaked by simulated body fluid composed of hydroxyapatite,Anatase,Rutile.Coatings by MAO-electrochemical deposition are superior in resisting wear compared with coatings by electrochemical deposition.SEM observation of the morphologies indicates that deposition time was shortened.

Rare earth/calcium phosphate composite coatings were fabricated on the surface of Ti-6Al-4V by micro-arc oxidation (MAO) technique. The wear properties and corrosion resistant of rare earth/ calcium phosphate composite coatings in the simulated body fluid (SBF) have been investigated and the bioactivity of the composite coatings were evaluated. The results show that the friction coefficient of the composite coatings in the SBF is only 0.15~0.18 and the anode polarization potential of the coating has been obviously enhanced about 0.18V compared with that of coatings of calcium phosphate coatings. So the composite coatings have excellent wear and corrosion resistant properties. XRD analysis indicates that the composite coatings can induce hydroxyapatite to form on its surface after soaked in SBF for 9d, which shows that the composite coatings own good bioactivity.

Rare earth/calcium phosphate composite coatings were prepared on the surface of Ti-6Al-4V by micro-arc oxidation (MAO) technique. The effect of the rare earth on the preparation of rare earth/calcium phosphate composite coatings and the friction and wear properties of the coatings in the simulated body fluid (SBF) has been investigated. The addition of rare earth may effectively improve the thickness of the coatings. The adhesion strength dipped with SBF and the friction and wear properties in the SBF of coatings have also been enhanced significantly compared with those of coatings of calcium phosphate coatings without rare-earth. The surface morphology and the phase composition of the MAO coatings were characterized by SEM and XRD, respectively. The results demonstrate that the porous morphology of the composite coatings is distributed more uniformly than that of the coatings without rare earth. XRD analysis indicates that the phase of calcium phosphate is slightly dependent on the addition of rare earth.

Micro-arc oxidation (MAO) is a novel technique for in situ ingrowing ceramic oxidation coatings on the surface of such nonferrous metals as Al, Mg, Ti and their alloys. The oxide coatings prepared by this technique have a dense structure, high adhesion and excellent integrated mechanical properties. Many studies have been carried out in this field recently. The recent progress of MAO technique at home and abroad is mentioned, characteristics of the general technique of MAO are introduced, the preparation methods, influence factors of preparation ceramic coatings and the application fields of MAO on titanium alloy are summarized, and the application prospects of this technique are explored.

TiO_2 bioceramic coatings were prepared on the surface of Ti-6Al-4V by micro-arc oxidation (MAO) technique.The effects of different oxidation voltage and pulsed frequency on microstructure,thickness and phase constitute of the coatings have been investigated.The results demonstrate that with the oxidation voltage increasing,the thickness of the coatings increase and with the pulsed frequency increasing,the thickness of the coatings decrease.SEM indicates that with the oxidation voltage increasing,the number of micro-pore of the coatings increase and with the pulsed frequency increasing,the surface roughness of the coatings increase.XRD analysis indicates that the mainly phase are anatase TiO_2,rutile TiO_2 and CaTiO_3.