Preparation And Physical Properties Of Ultrafine Grain Pure Titanium TiO₂-HA Composite Film

Objective:In order to prepare TiO₂-HA composite film with good hydrothermal characterization and physical properties on the surface of ultrafine grained pure titanium,better preparation parameters were obtained,which provided experimental basis for the application of ultrafine grained pure titanium in oral implant field.Method:Micro-arc oxidation treatment of ultra-fine crystal pure titanium and ordinary pure titanium specimens of a certain specification,micro-arc oxidation voltage is 400V,frequency is 500Hz,pulse width is 75?s,the time is 5min,the synthesis method is used to hydrothermally react the ultra-fine crystal pure titanium and the ordinary pure titanium after micro-arc oxidation to form a TiO₂-HA composite film layer.The test piece was placed in a hydrothermal synthesis reactor at 160?for 4 h,8 h,12 h,16 h hydrothermal synthesis,and ultrafine crystal pure titanium was used as the experimental group.The phase composition of the TiO₂-HA composite film was detected by XRD.The surface morphology of the TiO₂-HA composite film was observed by scanning electron microscopy and the thickness of the film was measured.The adhesion of the film layer to the substrate was measured by a coating adhesion automatic scratch tester.The friction and wear of the film layer was measured by a SFT-2M disk type friction and wear tester,and the hydrophilicity of the film surface was measured by a contact angle meter.A comprehensive analysis of the test results was carried out to obtain a preferred hydrothermal synthesis time for the preparation of TiO₂-HA composite film on the surface of ultrafine crystal pure titanium.Result:1.The results of XRD showed that HA was formed on the surface of ultrafine crystal titanium oxide film at 4h,8h,12h and 16h,and the intensity of HA diffraction peak increased with the increase of hydrothermal synthesis time;2.Scanning electron microscopy observation of the surface morphology see superfine crystal pure titanium TiO₂-HA composite film layer water formation at 4h,the amount of HA formed is small,and the distribution is uneven,mostly small crystal or agglomerate distribution,the formation of HA increased significantly when water was hot for 8 h,covering most of the porous surface,but HA still showed grain or agglomerate distribution,and no uniform film layer was formed.HA forms a uniform HA film layer when water is hot for 12h,completely covering the oxide film.Although the HA membrane layer was formed when the water was hot for 16 h,the distribution of HA agglomerates was visible on the surface;3.The thickness of the film was measured as the thickness of the ultrafine-grained pure titanium film at 4h,8h,12h,and 16h,which was5.365±0.381?m,6.940±0.708?m,8.648±0.454?m,9.665±0.696?m,respectively.The difference was statistically significant?P<0.05?.Increasing the thickness of the film gradually increases with the hydrothermal time;4.The binding force test results showed that the binding force values of hydrothermal heat at 4h,8h,12h and 16h ultrafine grained pure titanium film were 5.880±0.423N,7.450±0.590N,8.860±0.661N,6.430±0.303N,respectively.The difference was statistically significant?P<0.05?.As time increases,the binding force increases and then decreases,and the binding force value is maximum at 12h;5.The friction and wear test results show that the friction coefficient of ultrafine grained pure titanium TiO₂-HA composite film decreases first and then increases with the increase of hydrothermal time,and the friction coefficient is minimum at 12h.6.The contact angle test results showed that the average contact angles of the surface of the ultrafine grained pure titanium film at 4h,8h,12h and 16h during the hydrothermal time were 53.60°,51.60°,45.43°,44.80°,respectively.Contact angles between 40°and 60°are beneficial for cell adhesion and proliferation.Conclusions:When the ultra-fine grained pure titanium TiO₂-HA composite film was prepared by micro-arc oxidation and hydrothermal synthesis,the hydrothermal reaction parameters of the composite film with relatively good physical properties are as follows:hydrothermal synthesis temperature 160°C,hydrothermal time 12 h.