材料期刊网

通过微弧氧化技术在MB8镁合金表面形成微细表面结构,再利用自组装方法在微弧氧化层表面制备1H,1H,2H,2H-全氟葵烷基三氯硅烷（FDTS）自组装分子膜。采用扫描电镜、表面粗糙度仪、X射线衍射仪、表面硬度仪、接触角测量仪和UMT-2型摩擦磨损试验机评价膜层形貌结构、力学特性、润湿性及其微摩擦学特性。结果显示,镁合金表面经微弧氧化处理和自组装分子膜修饰后,表面润湿性经历了由亲水到超亲水再到超疏水的转变过程。超疏水表面的获得是由微弧氧化处理得到的表面粗糙结构和低表面能物质自组装分子膜共同作用的结果。对试样进行摩擦磨损测试的结果显示,致密层和疏松层以及经自组装分子膜修饰后的膜层均具有比镁合金基底更好的抗磨性能;基于自组装技术制备的疏水、超疏水表面形成的边界润滑膜在一定载荷条件下均能有效地减少基底的摩擦系数,边界润滑膜失效后,基底表面特性占主导地位。

Rough structure of MB8 magnesium alloy substrate were acquired by micro-arc oxidation and perflu- orodecyltrichlorosilane self-assembled monolayers deposited on the rough surface. Scanning electron micro- scope, surface profiler, X-ray diffractometer, surface hardness meter and contact angle measurement were used to analyse the surface properties and wettability of specimen. The micro-tribological behavior of specimens was evaluated on CERT UMT-2 tribometer. The results indicate that the wettability of substrate convert from hy- drophilicity to superhydrophilicity and superhydrophobicity after micro-arc oxidation and self-assembled mono- layers preparation. Rough structure of substrate by micro-arc oxidation and low surface energy material FDTS self-assembled monolayers are the main factors to prepare superhydrophobic surface. The results of tribological behavior of Si3 N4 ball and substrate surfaces indicate that compact layer, loose layer and their modified surfaces by SAMs all show a better anti-wear ability than bare magnesium alloy under the same testing condition. The hydrophobic and superhydrophobic boundary lubricating film formed by self-assembled monolayers can decrease the friction coefficient of base layer under certain load conditions. The tribological behavior depends on surface characteristics of base layer, if the boundary lubricating film is failed.