TC4钛合金表面阳极氧化制备TiO_2多孔膜的实验研究

以硫酸为电解液,钛合金(TC4)为阳极,不锈钢片为阴极,采用恒压的氧化方式在钛合金表面获得TiO2多孔膜。通过扫描电镜(SEM)观察了多孔膜的微观形貌并用X射线衍射(XRD)对覆在钛合金基体上的氧化膜进行了物相分析,研究了氧化工艺参数电压、阳极氧化时间和硫酸浓度对TiO2多孔膜相组成的影响。结果表明:TC4钛合金阳极氧化获得的氧化膜为非均一平面的TiO2多孔膜,且膜的孔径分布在90~240nm,XRD分析表明在不同的氧化工艺参数下氧化膜均由锐钛相和金红石相双相晶型组成。在0.5mol/L硫酸溶液中,电压高于100V或氧化时间长于5min即出现锐钛相和金红石相TiO2,随着电压的升高和时间的增长金红石相TiO2的含量逐渐增加;在恒压120V时,硫酸溶液浓度为0.3mol/L即出现锐钛相和金红石相TiO2,随着硫酸浓度的提高金红石相TiO2的含量先增加后减少。

Experimental Study of Preparation of TiO_2 Porous Films on the Surface of TC4 Titanium Alloy by Anodic Oxidation

TiO_2 porous films were prepared directly on the surface of TC4 titanium alloy by constant voltage anodic oxidation using sulfuric acid, TC4 and stainless steel plate as electrolyte, anode and cathode, respectively. The micro-morphology of the TiO_2 porous films on the substrate was observed by SEM. Meanwhile, phase composition of the porous films on the titanium alloy substrate was determined by XRD. The effects of oxidation process parameters such as the voltage, the anodization time and the concentration of sulphuric acid on the phase composition of TiO_2 porous films were investigated. The results showed that, oxide films of titanium alloy after anodic oxidation were heterogeneous TiO_2 porous films with pore size ranging from 90nm to 240nm. The XRD analysis showed that the oxide films prepared with different oxidation process parameters were all consisted of annatase and rutile phases. In 0.5mol/L sulfuric acid electrolyte, the annatase and rutile TiO_2 appeared when the voltage was higher than 100V or anodization time was longer than 5min, and with the voltage and time increasing the content of rutile TiO_2 increased gradually. The annatase and rutile TiO_2 appeared with 0.3mol/L sulfuric acid electrolyte at constant voltage (≥120V), and the content of rutile TiO_2 increased at first and then decreased with the increasing concentration of sulfuric acid.