Ti75钛合金微弧氧化膜的制备及性能

Preparation and properties of micro-arc oxidation coating on Ti75 titanium alloy

在含硅酸钠10g/L、六偏磷酸钠2g/L、柠檬酸钠2g/L和添加剂4g/L的电解液中,以微弧氧化技术在Ti75钛合金的表面成功制备了微弧氧化膜。采用涡流测厚仪、扫描电镜、X射线衍射仪、显微硬度计等手段研究了微弧氧化电压和时间对钛合金微弧氧化膜厚度的影响,分析了氧化膜层的表面形貌、组成、硬度、耐蚀性能及高温性能。结果表明,微弧氧化膜层主要由金红石型和锐钛矿型二氧化钛组成。氧化电压升高,膜层厚度增加;氧化时间延长,初期膜层厚度增加明显,20min后膜厚增加减缓。经微弧氧化处理后,钛合金的硬度、耐蚀性能和高温抗氧化性能均得到了明显改善。

A micro-arc oxidation （MAO） coating was successfully prepared on the surface of Ti75 titanium alloy by MAO technology in an electrolyte containing sodium silicate 10 g/L, sodium hexametaphosphate 2 g/L, trisodium citrate 2 g/L, and additive 4 g/L. The effects of MAO voltage and time on the thickness of MAO coating were studied by using eddy current coating thickness gauge, scanning electron microscopy, X-ray diffraction and microhardness tester. The surface morphology, composition, hardness, corrosion resistance and high-temperature property of the oxidation film were analyzed. The results indicated that the MAO coating is mainly composed of rutile and anatase titanium dioxides. The thickness of the MAO coating is increased with increasing oxidation voltage and it increases obviously with increasing oxidation time at the beginning and then basically becomes stable after 20 min. The hardness, corrosion resistance and high-temperature oxidation resistance of the titanium alloy are greatly improved by MAO treatment.