纯钛表面微弧氧化膜在模拟体液中的腐蚀行为

目的:研究在人工模拟体液中,纯钛表面微弧氧化膜的耐腐蚀性能。方法:在纯钛表面制备微弧氧化膜,利用扫描电镜、X射线衍射仪、表面粗糙度轮廓仪和电化学方法,分别观察其形貌特点、晶相结构、表面粗糙度,并测定其极化曲线。采用SPSS11.0软件包进行单因素方差分析。结果:微弧氧化处理后,纯钛表面生成微孔结构的氧化膜,微孔似火山丘状,直径约0.1～5μm。X射线衍射分析表明,膜层中含有金红石型、锐钛矿型二氧化钛及少量羟基磷灰石。微弧氧化后,试样表面粗糙度增加,轮廓算术平均偏差值(Ra)分别为(0.358±0.063)μm和(2.493±0.107)μm,微观不平十点高度值(Rz)分别为(2.662±0.628)μm和(16.519±1.028)μm。电化学实验表明,微弧氧化处理前后试样的自腐蚀电位、自腐蚀电流密度分别为-0.358V、0.55μA/cm2和-0.255V、0.80μA/cm2。结论:经微弧氧化技术处理后,纯钛表面形成微孔结构的二氧化钛膜层,表面粗糙度增加。在模拟体液中,钛的耐腐蚀性能明显提高。

Corrosion behavior of titanium with micro-arc oxidation in simulated body fluid

PURPOSE: To examine the corrosion resistance of micro-arc oxidation film on titanium by electrochemical methods in simulated body fluid. METHODS: Micro-arc oxidation film was formed on titanium surface by using micro-arc oxidation. The morphology, phase composition and the surface roughness were observed by scanning electron microscopy (SEM), X-ray diffraction(XRD) and profilemeter, respectively. Polarization curves in simulated body fluid was examined by electrochemical methods. SPSS11.0 software package was used for one-way ANOVA. RESULTS: On titanium surface with micro-arc oxidation, the film was consisted of many volcanic microporous, about 0.1microm -5microm in diameter. The film formed was a titanium oxide (TiO(2)) with peaks for both anatase and rutile phases, in addition, hydroxylapatite was also observed. Roughness increased on titanium surface. The self-corrosion potential and self-corrosion current density of titanium with micro-arc oxidation film were -0.255V and 0.80microA/cm(2) respectively, while those of untreated titanium were -0.358V and 0.55microA/cm(2). CONCLUSIONS: The results of electrochemical examinations indicate that micro-arc oxidation film increases the corrosion resistance of titanium.