Hydrothermal Modification And Bioactivity Of Microarc Oxidation Ceramic Coating On Pure Titanium

In this paper,the micro-arc oxidation technology is used to prepare an amorphous ceramic coating containing calcium and phosphorus on the surface of pure titanium,and the bioactive coating structure is constructed by the subsequent conventional hydrothermal treatment and microwave hydrothermal treatment.At the same time,by changing the process parameters of the hydrothermal process,the coating structure and biological activity can be adjusted.X-ray diffraction,scanning electron microscope,transmission electron microscope and X-ray energy dispersive spectrometer were used to analyze the phase composition,micro-morphology,element types and element content of the coating surface before and after conventional hydrothermal and microwave hydrothermal treatment.Etc.,and the inducibility of apatite on the surface of the coating after immersing the simulated body fluid;the simulated body fluid immersion experiment was carried out on the sample,and the apatite deposited on the surface of the micro-arc oxidation coating before and after conventional hydrothermal and microwave hydrothermal treatment was evaluated by SEM and EDS..The components of tungsten used in the process of micro-arc oxidation are EDTA-2Na,Ca(CH3COO)2·H2O,Ca(H2PO4)2·H2O,Na2 Si O3·9H2O,Na OH and H2O2 aqueous solution,and the surface of pure titanium after micro-arc oxidation treatment Form a microporous structure.Na OH solution and Ca Cl2 solution were used as hydrothermal solutions for conventional hydrothermal treatment.There were hydroxyapatite nanorods and Na0.23 Ti O2 in Na OH solution.Only hydroxyapatite nanorods were formed on the surface of the coating in Ca Cl2 solution and the quantity was more.The thermodynamics and kinetics of HA in conventional hydrothermal processes are simulated and calculated.The increase of hydrothermal temperature and solution concentration can increase the nucleation driving force and nucleation rate of HA,and the calculation result of Ca Cl2 solution is better than that of Na OH solution.The increase of p OH is not conducive to the growth of HA nucleation.Adding Sr2+ as a hydrothermal solution in Ca Cl2 solution,for conventional hydrothermal treatment,the increase of hydrothermal temperature will increase the number of Sr-HA nanorods on the coating surface,and the prolongation of the treatment time is also conducive to the formation of Sr-HA nanorods and For microwave hydrothermal treatment,the increase of hydrothermal temperature can increase the number and crystallinity of Sr-HA nanorods on the coating surface.If the concentration of the mixed solution is too high,no Sr-HA nanorods will form on the surface of the coating.If the treatment time is too long,the number of Sr-HA nanorods on the coating surface after microwave hydrothermal treatment is the same under the same process parameters,and the crystallinity is better.Simulated body fluids were immersed in micro-arc oxidation decomposition before and after conventional hydrothermal and microwave hydrothermal treatment.After 7 days of micro-arc oxidation coating immersion,no apatite was deposited on the surface,showing extremely poor in vitro biological activity;After 7 days of crushing,the coating surface was completely covered by apatite,showing good biological activity;and after 7 days of microwave hydrothermal treatment,the coating surface was not only completely covered by apatite,but also apatite.In summary,after the conventional hydrothermal and microwave hydrothermal treatment of the micro-arc oxidation accessories,the in vitro biological activity has been significantly improved.