MoS_(2)-C异质复合薄膜的真空超滑行为及其机制研究  

Superlubricity Behavior and Mechanism of MoS_(2)-C Heterostructure Composite Films in Vacuum

作　　者：李煊禹 吉利[2] 刘晓红[2] 孙初锋[1] 李红轩[2] LI Xuanyu;JI Li;LIU Xiaohong;SUN Chufeng;LI Hongxuan(Key Laboratory of Environment-Friendly Composite Materials of the State Ethnic Affairs Commission,School of Chemical Engineering,Northwest Minzu University,Gansu Lanzhou 730030,China;State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Gansu Lanzhou 730000,China)

机构地区：[1]西北民族大学化工学院环境友好复合材料国家民委重点实验室,甘肃兰州730030 [2]中国科学院兰州化学物理研究所固体润滑国家重点实验室,甘肃兰州730000

出　　处：《摩擦学学报》2023年第10期1140-1150,共11页Tribology

基　　金：国家自然科学基金(U2141210,52167003);甘肃省重点研发项目(21YF5WA064);中国科学院青年创新促进会项目(Y202084)和中国科学院兰州化学物理研究所重大突破项目(KJZLZD-3)资助。

摘　　要：采用闭合场非平衡磁控溅射技术制备了MoS_(2)-C异质复合薄膜,利用多环境可控摩擦试验机测试了薄膜在真空环境中的摩擦学性能,通过拉曼光谱仪(Raman)、X射线衍射仪(XRD)和透射电子显微镜(TEM)等表征手段分析了薄膜摩擦前后结构的变化,探讨了超润滑机理.结果表明:复合薄膜呈现致密的“纳米晶/非晶”结构,在真空中具有优异的摩擦学性能,保持了超低摩擦系数(0.006~0.009)和磨损率[1.026×10^(-7)mm^(3)/(N·m)],达到了超润滑状态.摩擦过程中碳选择性转移到钢球表面形成非晶碳转移层,薄膜磨痕表面形成有序的MoS_(2)(002)晶面,摩擦发生在MoS_(2)有序晶体和非晶碳转移膜之间,形成非公度异质接触,降低摩擦系数实现超润滑.钢球/MoS_(2)-Ti、a-C:H/MoS_(2)-Ti摩擦配副在相同条件下的不同摩擦行为,也证明了上述超润滑机理.Molybdenum disulfide(MoS_(2))shows excellent lubricating properties in high vacuum condition due to its unique layered structure.But passivation to oxygen atmosphere like ambient air makes tribological performance lower.Although the a-C:H films exhibit super-low friction coefficient and wear rate in N2 condition,the long duration for super-low friction seems to be an important issue for its application in high vacuum.This paper aimed to combine MoS_(2)and a-C:H films to meet the requirements of high vacuum condition and super-low friction coefficient and long wear life under practical working conditions.Based on this,firstly,MoS_(2)-C composite films were deposited by closed field unbalanced magnetron sputtering technology.The tribological properties of the films were tested by HVTRB in vacuum condition.The structure changes of the film before and after friction were analyzed by Raman,XRD,TEM and other analytical techniques.And the superlubricity mechanism was investigated in this study.It suggested that the composite films exhibit a dense"nanocrystalline/amorphous"microstructure,which maintain super-low friction coefficient(0.006~0.009)and wear rate[1.026×10^(-7)mm^(3)/(N·m)],reaching a superlubricity state.The wear tracks and wear scars were observed by a three-dimensional profiler.It revealed that the contact area was covered with thin transfer film,while a small amount of wear debris distributed around.Furthermore,different from the as-deposited films,it was observed by Raman that MoS_(2)peak around 380 cm^(-1) and 410 cm^(-1) of the wear track was obviously enhanced.A broad peak at 1200~1600 cm^(-1),indentified as amorphous carbon,was observed on the wear scar.During the friction process,C was selectively transferred to the surface of the steel ball to form an amorphous carbon transfer film.Meanwhile,the relatively disordered structure became more ordered,resulting in the presence of well aligned MoS_(2)in the interface,which was prone to shear the basal plane oriented along the sliding direction.The frict

关 键 词：MoS_(2)-C复合薄膜 超润滑 真空 摩擦学性能 非公度接触 

分 类 号：TH117.1[机械工程—机械设计及理论]