钙盐浓度对复合氧化法制备多孔二氧化钛涂层表面结构的影响

Effect of Calcium Concentration in Micro-arc Oxidation Electrolyte on the Surface Structure of Porous Titania Coatings by Compound Oxidation Process

为了分析微弧氧化电解液中钙盐浓度对复合氧化法(即预氧化和微弧氧化复合处理)制备多孔二氧化钛涂层表面结构的影响,利用X射线衍射、扫描电镜及附带的能谱对涂层的表面相结构、形貌及元素组成进行了观测与分析,利用图像分析软件对涂层表面孔隙率进行测试。结果表明:复合氧化法制备的多孔二氧化钛涂层表面均含有单质钛、锐钛矿型二氧化钛和金红石型二氧化钛;钙盐浓度的变化对涂层表面结构有一定影响,随着钙盐浓度的增加,涂层中锐钛矿型二氧化钛相对含量减少,金红石型二氧化钛相对含量增加;涂层表面的钙、磷元素含量降低,钙磷原子比增加;在所选钙盐浓度下,表面孔隙率的变化不十分显著。

In order to study the effect of calcium concentration in the micro-arc oxidation electrolyte on the surface structure of porous titania coatings by compound oxidation process (pre-oxidation and micro-arc anodic oxidation), X-ray diffusion and the scanning electronic microscopy equipped with EDS were used to analyze the morphologies, phase structures, element compositions of the coatings. An image analysis software was employed to calculate the porous ratio to the surface area. The results show that the coatings formed by the compound process were all composed of titanium, anatase and rutile. The calcium concentration has certain effect on the surface structure. With the increase of calcium concentration, relative amount of the anatase reduces and the rutile increases; The content of calcium and phosphorus in the coatings decreases and the atomic ratio of Ca/P rises. Variation of the calcium concentration has no remarkable influence on the surface porous ratio of the coatings in the selected phosphate concentrations.