| The potassium titanate (K2Ti6O13) ceramic has good bioactivity and biocompatibility, and has been a new generation of biological coating material with high bonding strength, so it is of great significance to study its preparation process and relative properties. This paper prepared K2Ti6013coating on titanium substrate by electrochemical and hydrothermal technology, to obtain coating with high bioactivity and excellent corrosion resistance. Firstly, TiO2oxide film was prepared on pure substrate by anodic oxidation technology, and optimal preparation condition was determined. Then K2Ti6O13/TiO2coating and coatings with titanate nanostructures were prepared through electrochemical and hydrothermal treatment respectively. The prepared coatings were characterized by SEM, TEM, Raman spectroscopy, XRD, electrochemical test and bioactivity measurement.The results show, with the increase of anodic oxidation voltage from10V to30V, or time from10min to60min in0.5mol/1H2SO4solution, the oxide film produced changed from smooth surface to protuberance shape, and the protuberance cracked at too large potential or time. Considering morphology and corrosion resistance property of the produced oxide film, the optimal preparation condition for anodization is at20V for30min. Compared to coating as control sample prepared by traditional chemical immersion, porous network K2Ti6O13/TiO2coatings were obtained through constant-current electrolysis in3mol/1KOH solution, and it highly improved the corrosion resistance of Ti substrate. The morphology of coating did not change much at different current densities, but it fell off with current densities over20mA/cm2, the preparation current density should be controlled under10mA/cm2. A new apatite layer was formed on the coating after simulate body fluid (SBF) immersion, and the sample electrochemically modified has better bioactivity than the control sample. Meanwhile, we also carried out hydrothermal treatment on Ti sample before and after anodization, and synthesized nanobelts with heterogeneous shape and homogeneous nanowires, and they are both composed of K2Ti6O13and H2Ti2O5·H2O The coating with uniform nanowires prepared by anodization-hydrothermal treatment exhibited longer passive area, lower corrosion current and bigger impedance than sample treated by direct hydrothermal method, and greatly enhanced corrosion resistance of Ti substrate. A new apatite layer was formed on the coating after simulate body fluid (SBF) immersion, and the sample modified has good bioactivity. The anodizaiton treatment can not only accelerate the process of forming nanowire, but also tailor the morphology by influencing the nanowire orientation. There are36figures,12tables and76references. |
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