氮化碳增强聚四氟乙烯摩擦学性能的分子动力学模拟

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. 

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

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.