润湿性梯度对仿生织构表面摩擦学行为的影响  

Effect of Wettability Gradient on Tribological Behavior of Biomimetic Textured Surfaces

作　　者：王胡军 谢正灿 赵修远 田炉林 郑靖[1] WANG Hujun;XIE Zhengcan;ZHAO Xiuyuan;TIAN Lulin;ZHENG Jing(Tribology Research Institute,School of Mechanical Engineering,Southwest Jiaotong University,Sichuan Chengdu 610031,China)

机构地区：[1]西南交通大学机械工程学院摩擦学研究所,四川成都610031

出　　处：《摩擦学学报（中英文）》2024年第3期300-311,共12页Tribology

基　　金：四川省科技计划项目(2023NSFSC0863);国家自然科学基金项目(52105212);中国博士后科学基金项目(2021M702712);工程仿生教育部重点实验室开放基金(K202205)资助。

摘　　要：润湿性调控和仿生织构设计是实现表面减摩耐磨的重要方法.利用飞秒激光在AISI 440C不锈钢表面制备了仿生微凹坑,在微凹坑中沉积润湿性可调的超疏水涂层,通过紫外线辐照构筑了4种梯度润湿性仿生织构表面.采用往复滑动摩擦磨损试验,以水为润滑剂,对比研究了不同载荷和速度下润湿性梯度对仿生织构表面摩擦学行为的影响.结果表明,在低载高速条件下,当表面形成低黏附性超疏水-弱疏水的润湿性梯度时,耐磨性最佳,相较于AISI 440C不锈钢抛光表面,磨损率降低47.9%,说明润湿性梯度耦合仿生织构能够有效减小磨损.With the rapid development of modern industry, higher technical requirements are put forward for the friction reduction and wear resistance of the surfaces/interfaces of mechanical parts. Wettability regulation and biomimetic texture design are important methods to achieve friction reduction and wear resistance, but the coupling effects of wettability gradient and biomimetic textures on tribological behaviors have rarely been investigated. In this paper,femtosecond laser was used to fabricate biomimetic microdimples with diameter of 50 μm, spacing of 100 μm, and depth of 15 μm on the smooth surfaces of AISI 440C stainless steel. We also prepared an environmentally friendly superhydrophobic coating with tunable wettability, which was composed of TiO2 and polyurethane-modified silicone. The coating was deposited in the microdimples to fabricate biomimetic textured surfaces with wettability gradient. To demonstrate the successful fabrication of the surfaces, the microscopic morphology and elemental composition were analyzed by scanning electron microscope(SEM) and energy dispersive spectrometer, respectively. The results showed that the superhydrophobic coatings were deposited in the biomimetic textures and the flat regions outside the textures were not covered by the coatings. Then, four biomimetic textured surfaces with different wettability gradients(contact angles of coatings = 156°, 120°, 50° and 0°, respectively) were constructed by UV irradiation. The tribological behaviors of the four surfaces under different loads(0.5, 1.0, 2.0, 4.0 N) and frequencies(3, 6, 9, 12 Hz) were comparatively studied. Reciprocating tribological experiments were performed under 20 μL water lubrication. The reciprocating stroke and test duration were set to 4 mm and 15 min, respectively. The wear rate was calculated after examining the profiles of wear scars using laser confocal microscopy. The microscopic morphologies of wear scars were characterized by SEM.The results showed that wear rates decreased with the increases in

关 键 词：润湿性梯度 仿生织构 水润滑 耐磨 飞秒激光 

分 类 号：TH117.1[机械工程—机械设计及理论]