氧化处理时间对纯钛微弧氧化膜表面性能的影响

Effect of processing lime on the surface properties of titanium micro-arc oxidation film

目的探索氧化处理时间对纯钛微弧氧化膜层表面性能的影响，为微弧氧化技术的临床应用提供依据。方法将44个直径10mm厚1mm的圆盘形纯钛片等分为4个组，置于含0.2mol／L乙酸钙和0．02mol／Lβ-甘油磷酸二钠盐的电解液中进行微弧氧化处理，氧化处理时间分别为1、5、10和15min，检测试件表面形貌、化学组成、晶相结构、粗糙度、表面自由能等性能。结果随着处理时间由1min延长至15min，膜层表面平均孔隙尺寸由（1．30±0．07）μm增大至（1．55±0．09）μm；膜层厚度由（10．2±1．1）μm增加至（20．9±2．9）μm；Ca／P由1．99增大至2．45；表面自由能由24．62ml／m。增加到39．49ml／m2；锐钛矿型TiO：逐渐减少，金红石型TiO2逐渐增多。当氧化时间为15min时，膜层出现剥落。结论处理时间可影响纯钛表面微弧氧化膜层厚度、表面形貌、晶相结构、表面自由能等性能；氧化时间为5～10min时，所获得膜层有较理想的表面性能。

Objective To explore the effect of changes of processing time on the surface properties of titanium coating formed by micro-arc oxidation （MAO）. Methods Forty-four disc-shaped pure titanium specimens with 10 mm diameter and 1 mm thickness were equally divided into 4 groups and processed by MAO technique in electrolytes containing 0. 2 mol/L calcium acetate （ CA ） and 0. 02 mol/L 13-glycerol phosphate disodium salt pentahydrate （13-GP）. The processing time were set at 1 min, 5 min, 10 min and 15 min respectively. The topograph of the MAO film surface and the film-substrate interface was observed by a scanning electron microscopy （SEM）, and the composition was analyzed by an energy dispersive spectroscope （EDS） incorporated in the SEM. The phase and the microstructure of the film were analyzed by X-ray diffraction （XRD）. The roughness of the film was measured using a roughness tester. The surface static contact angle was detected by a contact angle measurement instrument and the surface energy was calculated accordingly. Results With the increase of processing time from 1 min to 15 min, the pore size increased from （1.30 ±0. 07） μm to （ 1.55 ±0. 09）μm, and film thickness increased from （ 10. 2 ± 1.1 ） μm to （20. 9 ±2. 9） μm. The content of the Ca in the film increased accordingly, and Ca/P increased from 1.99 to 2.45, and the surface energy increased from 24. 62 ml/m2 to 39.49 ml/m2. Meanwhile, the XRD pattern indicated that rutile increased but anatase and titanium decreased gradually. At the time of 15 min, part of the MAO film peeled off. Conclusions Processing time has impact on the thickness, surface topography, crystal component and surface energy of titanium MAO coating. MAO film treated for 5-10 min demonstrated favorable surface properties.