N掺杂对Si-DLC薄膜的结构性能影响及摩擦机理研究  

Understanding the Role of N-Incorporation on the Structure and Properties of Si-DLC Film and the Tribological Mechanism

作　　者：魏徐兵 冯海燕 尹萍妹 陈赞 丁佳晴 卢诗琪 杜乃洲 李晓伟[1] 张广安[2] WEI Xubing;FENG Haiyan;YIN Pingmei;CHEN Zan;DING Jiaqing;LU Shiqi;DU Naizhou;LI Xiaowei;ZHANG Guangan(School of Materials Science and Physics,China University of Mining and Technology,Jiangsu Xuzhou 221116,China;State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Gansu Lanzhou 730000,China)

机构地区：[1]中国矿业大学材料与物理学院,江苏徐州221116 [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（中英文）》2024年第9期1266-1282,共17页Tribology

基　　金：国家自然科学基金项目(52305237);中央高校基本科研业务费专项资金(2023QN1036);江苏省卓越博士后计划项目(2022ZB522);徐州市科技计划项目(KC21041)资助。

摘　　要：采用平板阴极等离子体增强化学气相沉积技术,通过调控N_(2)流量在GCr15基底上制备了系列硅氮共掺杂类金刚石碳基(Si/N-DLC)薄膜,分析探索N掺杂对于Si-DLC薄膜结构、力学性能和摩擦学行为的作用规律以及Si/NDLC薄膜的低摩擦磨损机理.结果表明:N元素的引入促进Si-DLC薄膜中sp^(2)-C结构的形成,降低了薄膜的硬度和弹性模量,但能大幅改善Si-DLC薄膜的韧性并增强结合(>20 N).更重要的是,N掺杂可有效降低Si-DLC薄膜的摩擦系数并改善其耐磨性能,摩擦系数和磨损率相较于Si-DLC薄膜分别降低了约26%和45%.其摩擦机理是类石墨碳(GLC)转移膜的形成使得摩擦界面发生转移,有效降低了Si/N-DLC薄膜的摩擦系数,并且依赖于摩擦界面的石墨化程度和氢含量.而磨损行为取决于其薄膜自身韧性和抵抗弹塑性变形的能力,磨痕内部脆性断裂缺口会造成转移膜的大面积破坏,加剧了黏着磨损.此外,确定了Si/N-DLC薄膜低摩擦(摩擦系数≤0.05)的最佳服役区间,相关结果为Si/N-DLC薄膜的结构性能调控和工程应用提供参考.Si/N-DLC films were deposited to analyze and explore the role of N-incorporation on the structure,mechanical properties and tribological behaviors of Si-DLC films and the low friction and wear mechanism of Si/N DLC films by controlling the flow of N_(2) precursors,which taken advantage of plane cathode plasma enhanced chemical vapor deposition(PC-PECVD)technology.The results showed that the surface and cross-sectional morphologies of asdeposited Si/N-DLC film were uniform and compact,and the microscopic defects and cracks were not observed.No stratification was observed between the substrate and the transition layer,and between the transition layer and Si/N-DLC film,exhibiting an excellent adhesion.The introduction of N element induced the formation of ring sp^(2) carbon structure in DLC films,resulting in the increase of sp^(2)-C content in Si-DLC films,in other words,N-incorporation leaded to the graphitization transition of Si-DLC structure,meaning that the structure of Si-DLC films was more orderly.Besides,the reduction of sp3 fraction caused by N-incorporation increased the hardness and elastic modulus of the films.Interestingly,with the enhancement of N content,the toughness of Si-DLC films and the adhesion with the substrate exhibited a trend of first increasing and then decreasing.The incorporation of a appropriate amount of N element(50 sccm)improved significantly the toughness and the adhesion(>20 N).More importantly,N-incorporation effectively reduced the friction coefficient of Si-DLC film and improved the wear resistance.Compared with Si-DLC film,Si/N-DLC films generally showed lower friction coefficient and wear rate,which decreased firstly and the increase with the improvement of N content.Si/N-DLC film deposited with the N2 flow of 75 sccm showed the lowest friction coefficient(0.0395)and wear rate[1.63×10^(−7)mm^(3)/(N·m)],which were reduced by about 26%and 45%compared with the Si-DLC film(0 sccm),respectively.The friction mechanism was that the formation of graphite-like carbon(GLC)transfer

关 键 词：Si/N-DLC薄膜 摩擦磨损 润滑机理 GLC转移膜 滑动界面 

分 类 号：TH117.1[机械工程—机械设计及理论] TB321[一般工业技术—材料科学与工程]