陶瓷框架增强聚四氟乙烯仿生复合材料及其摩擦学性能研究  

Bioinspired Ceramic Scaffold Reinforced Polytetrafluoroethylene Composite and Its Tribological Properties

作　　者：伍雨驰 雷磊 刘旻帑 赵仲航 郑靖[1] 周仲荣[1] WU Yuchi;LEI Lei;LIU Mintang;ZHAO Zhonghang;ZHENG Jing;ZHOU Zhongrong(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10期1429-1440,共12页Tribology

基　　金：国家自然科学基金项目(52075459,52305217)资助。

摘　　要：针对聚四氟乙烯自润滑复合材料耐磨性差这一工业润滑领域的瓶颈问题,本研究中受人牙釉质釉柱/釉间质微观结构的抗磨作用机制启发,基于有限元分析和1种乙酸锆改进的定向冷冻技术,设计制备了定向多孔氧化锆陶瓷框架增强聚四氟乙烯仿生复合材料,并对其力学性能和摩擦学行为进行了试验研究.结果表明:仿生复合材料的自润滑性能良好,力学性能和耐磨性远优于聚四氟乙烯和商用聚四氟乙烯自润滑复合材料易格斯.与易格斯材料相比,仿生复合材料的硬度提高约1.8倍,弹性模量提高约15.2%,抗压强度提高约2.8倍,磨损体积降低约76.6%.仿生复合材料优异的摩擦学性能与定向多孔陶瓷框架增强结构密切相关,这种陶瓷框架增强结构具有Voigt模型(复合材料承载能力上限)承载特性,能够大幅提高复合材料的承载能力,避免材料表面发生严重变形和破坏,提高耐磨性.同时,仿生复合材料的氧化锆陶瓷框架占比仅为25.6%(体积分数),高含量的聚四氟乙烯填料能够有效地在摩擦接触界面形成自润滑转移膜,实现良好润滑.The development of self-lubricating polytetrafluoroethylene-based composites with excellent wear resistance is urgently required for industrial lubrication applications,yet it remains a key challenge.Herein,inspired by the anti-wear mechanism of the rod/inter-rod microstructure of human tooth enamel,we present a biomimetic design strategy for creating aunidirectional porous ceramic scaffold reinforced polytetrafluoroethylene composite that achieves an elegant combination of tribological properties.The design and fabrication of the bioinspired composite were accomplished using finite element simulations and a directional freeze-casting technique modified with zirconium acetate.Simulation results indicated a significant enhancement in the load-bearing capacity of the bioinspired composite when the volume fraction of ceramic scaffold surpassed 20%.Accordingly,the bioinspired composite with a ceramic volume fraction of 25.6%was prepared and tested in this study.Vickers indentation tests,uniaxial compression tests,and reciprocating sliding wear tests were conducted to assess the mechanical and tribological properties of the bioinspired composite.Microscopic morphology and composition analysis techniques,including scanning electron microscopy,energy-dispersive X-ray spectroscopy,and X-ray photoelectron spectroscopy,were employed to investigate the wear mechanism of the bioinspired composite.The results demonstrated that the bioinspired composite had encouraging performance characterized by a self-lubricating capacity comparable to that of polytetrafluoroethylene and Igus material(a commercially available self-lubricating polytetrafluoroethylene-based composite),as well as significantly superior mechanical properties and wear resistance.Under the given friction condition,the bioinspired composite had a steady-state friction coefficient of 0.21,meeting the criteria for the application of self-lubricating polymer materials.Compared with the Igus material,the bioinspired composite showed an increase in the hardness,elastic

关 键 词：聚四氟乙烯复合材料 定向多孔陶瓷框架 仿生设计 耐磨性能 自润滑 

分 类 号：TH117.1[机械工程—机械设计及理论] TB332[一般工业技术—材料科学与工程]