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为提高钛合金的摩擦学性能,采用激光加工技术在Ti6Al4V合金表面分别构建间距为100和300μm的网格和点阵微结构,将SiO_2纳米粒子涂覆在微结构上制备微纳结构。用接触角测量仪测量试样的表面接触角和滚动角;用LEXT OLS4000 3D激光共聚焦显微镜进行表面形貌和磨痕表征,采用多功能摩擦磨损试验机(UMT)进行摩擦学性能测试。结果表明,具有微结构的表面是符合Wenzel状态的疏水表面,涂覆SiO_2具有微纳结构的表面是符合Cassie状态的超疏水表面。微结构间距100μm的表面的疏水性强于300μm,网格表面疏水性强于点阵。随表面疏水性能的增强,磨痕深度变浅。在50 m N载荷条件下,涂覆SiO_2表面的摩擦系数约为激光加工表面的0.6倍,网格表面的摩擦系数约为点阵的0.8倍。在5 N载荷条件下,涂覆SiO_2减小摩擦系数曲线的波动性。
In order to improve the tribological properties of titanium alloy, the grids and lattice microstructures with spacing of 100 and 300μm were fabricated on the surface of Ti6Al4V alloy by laser machining. The microstructure was prepared by coating SiO_2 nanoparticles on the microstructure. The contact angle and rolling angle of the sample were measured by the contact angle measuring instrument. The surface morphology and wear marks were characterized by LEXT OLS4000 3D confocal laser scanning microscope. The tribological properties of the samples were tested by the multi-purpose friction and wear tester (UMT). The results show that the surface with microstructure is a hydrophobic surface that conforms to Wenzel state. The surface of the coating with SiO 2 with micro-nano structure is a Cassie-state superhydrophobic surface. The surface of the microstructure with a pitch of 100μm is more hydrophobic than 300μm, and the surface of the mesh is more hydrophobic than the lattice. With the enhancement of surface hydrophobicity, the depth of wear scar becomes lighter. Under the load of 50 m N, the friction coefficient of the coated SiO 2 surface is about 0.6 times that of the laser processed surface, and the friction coefficient of the grid surface is about 0.8 times of that of the lattice. Coating SiO 2 at 5 N load reduces the volatility of the friction coefficient curve.