氮化碳增强聚四氟乙烯摩擦学性能的分子动力学模拟  

Molecular Dynamics Simulation on the Tribological Properties of the Carbon Nitride Reinforced PTFE

作　　者：雷浩 赵盖 尹宇航[1] 丁庆军 时运来 LEI Hao;ZHAO Gai;YIN Yuhang;DING Qingjun;SHI Yunlai(School ofAeronautics,Nanjing University of Aeronautics and Astronautics,Jiangsu Naming 210016,China;State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Chinese Academy of Science,Gansu Lanzhou 730000,China)

机构地区：[1]南京航空航天大学航空学院,江苏南京210016 [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》2021年第2期223-229,共7页Tribology

基　　金：国家自然科学基金(51975282);固体润滑国家重点实验室开放基金(LSL1901)项目资助。

摘　　要：采用分子动力学模拟的方法研究氮化碳(C3N4)对聚四氟乙烯(PTFE)摩擦学性能的影响.首先,建立了纯聚四氟乙烯和氮化碳/聚四氟乙烯复合材料两个无定型模型,优化后分别计算其机械性能.模拟结果显示:加入氮化碳后,聚四氟乙烯的杨氏模量和剪切模量分别提高了218%和141%.然后为了计算摩擦学性能,建立了与铜对摩的摩擦模型,对金属铜层施加一定的载荷和速度进行滑动磨损.模拟结果显示:纯聚四氟乙烯的摩擦系数为0.144,磨损率为27.6%;氮化碳/聚四氟乙烯基体的摩擦系数为0.118,未见明显的磨损.最后通过提取摩擦界面温度、原子运动速度、原子相对浓度、径向分布函数和结合能等数据,从原子尺度揭示了氮化碳对聚四氟乙烯摩擦学性能的作用机制.This paper studied the effect of carbon nitride(C3N4)on the mechanical and tribological properties of polytetrafluoroethylene(PTFE)by molecular dynamics simulation.Firstly,the amorphous models of pure PTFE and C3N4/PTFE composites were established and the mechanical properties were calculated after structural optimization.The simulated results showed that the Young’s modulus and shear modulus of the PTFE were increased by 218%and 141%after C3N4 reinforcement,respectively.Secondly,the friction model of PTFE composites sliding against copper was established and simulated under certain load and speed in order to investigate the friction and wear behavior.The simulated results showed that the friction coefficient of pure PTFE was 0.14 and its wear rate was 27.6%,while the friction coefficient of C3N4/PTFE composite decreased to 0.11 without obvious wear.Finally,the interaction mechanisms between PTFE composites and copper were revealed by analyzing the variations of relative atomic concentration,atomic velocity,interface temperature,radial distribution function,and binding energy.

关 键 词：聚四氟乙烯 氮化碳 摩擦 磨损 分子动力学模拟 

分 类 号：TB332[一般工业技术—材料科学与工程]