阳极氧化Ti-6Al-4V合金表面TiO2多孔膜的制备及研究

Preparation and Study of TiO_2 Porous Film on the Surface of Ti-6Al-4V Alloy by Anodic Oxidation

在一定浓度的H_2SO_4溶液中对Ti-6Al-4V合金表面进行阳极氧化处理,通过改变阳极氧化处理的电压、氧化时间和电解液浓度,研究了预处理工艺参数对钛合金表面形貌、物相、润湿性及粗糙度的影响.试验结果表明:钛合金经过阳极氧化处理后,表面出现了二氧化钛(TiO_2)纳米多孔结构,多孔氧化膜由锐钛矿型和金红石型TiO_2组成;在0.5mol·L^(-1)H_2SO_4溶液中,随着阳极氧化电压的增加,多孔膜的孔径逐渐增大,基体表面与模拟体液(SBF)的接触角明显降低,经120V氧化处理的试样表面接触角由预处理前的52.8°降至16.9°左右,具有良好的润湿性;并且试样表面的粗糙度明显增加,在电压为120V时粗糙度达到0.56μm.在电压120 V时,随着阳极氧化时间或电解液浓度的增加,TiO_2多孔膜的含量和孔径尺寸逐渐增大,试样表面的润湿性和粗糙度也不断增加,在氧化时间10 min或电解液浓度0.5 mol·L^(-1)时达到最大,氧化时间大于10 min或电解液浓度高于0.5 mol·L^(-1)时,试样表面出现裂纹,多孔结构被破坏.

Ti-6Al-4V alloys were anodized in H_2SO_4 solution.The study was to investigate the effect of anodic oxidation parameters(the anodizing voltage,the oxidation time and the concentration of sulfuric acid)on the morphology,phase,wettability and surface roughness of Ti-6Al-4V substrates.The results indicated that TiO_2 porous oxide films consisting of annatase and rutile phases were achieved directly on the surface of Ti-6Al-4V substrates after anodic oxidation.In0.5 mol·L^(-1) H_2SO_4 solution,the pore size of the titania layer increased with the anodizing voltage increased.The contact angle on the surface of Ti-6Al-4V decreased obviously after anodic oxidization treatment,and the contact angle of the sample at 120 V had dropped to about16.9 degree from52.8 degree,which has good wettability.Moreover,the roughness increased with the increaseof voltage and reached about 0.56μm at 120 V.The content and the pore size of TiO_2 porous oxide film increased gradually with the increasing of the oxidation time and the concentration of sulfuric acid.The wettability and surface roughness of substrates were also improved,which reached the best for 10 min or in0.5 mol·L^(-1) H_2SO_4 solution.The oxide films were damaged when the oxidation time was longer than 10 min or the concentration of sulfuric acid was higher than0.5 mol·L^(-1).