改性纳米氮化硅增强聚四氟乙烯复合涂层摩擦学行为研究  

Tribological Behavior Investigation of Polytetrafluoroethylene Composite Coating Reinforced with Modified Nano-Silicon Nitride

作　　者：周红成 卞达 刘雅玄 郭永信 赵永武 ZHOU Hongcheng;BIAN Da;LIU Yaxuan;GUO Yongxin;ZHAO Yongwu(School of Mechanical Engineering,Jiangnan University,Wuxi 214122,China)

机构地区：[1]江南大学机械工程学院,江苏无锡214122

出　　处：《中国材料进展》2022年第7期578-583,共6页Materials China

基　　金：国家自然科学基金资助项目(51675232);江苏省青年自然科学基金资助项目(BK20190611)。

摘　　要：聚四氟乙烯(PTFE)在减摩材料领域应用广泛,但其较差的耐磨性限制了其应用。纳米材料改性是改善PTFE耐磨性的一种有效方法,而氮化硅(Si_(3)N_(4))的强度高、摩擦系数低,能够与PTFE实现功能互补。以PTFE和硅烷偶联剂KH-570改性的Si_(3)N_(4)为填料、聚酰胺酰亚胺(PAI)为粘结剂,采用喷涂-固化的方法制备了PTFE/Si_(3)N_(4)复合涂层,并对该涂层的摩擦学性能展开了研究。利用扫描电子显微镜(SEM)和傅里叶变换红外光谱(FT-IR)对改性前后的Si_(3)N_(4)纳米颗粒进行表征;利用显微硬度测试仪和摩擦磨损试验机对PTFE/Si_(3)N_(4)复合涂层的综合性能进行表征。研究结果表明:KH-570成功接枝到了Si_(3)N_(4)纳米颗粒的表面,接枝后Si_(3)N_(4)纳米颗粒的表面更加粗糙,有利于其均匀分散;Si_(3)N_(4)纳米颗粒可以改善PTFE/Si_(3)N_(4)复合涂层的硬度和摩擦学性能。当改性Si_(3)N_(4)纳米颗粒的质量分数为1%时,复合涂层的硬度最高,为11.1HV,摩擦系数和磨损率最低,分别为0.0755和3.78×10^(-3) m^(3)·N^(-1)·m^(-1),磨损方式为磨粒磨损。当加入过多的改性Si_(3)N_(4)纳米颗粒时,其会出现团聚,复合涂层的摩擦磨损性能下降。Polytetrafluoroethylene(PTFE)is widely used in the field of antifriction materials,but its poor wear resistance limits its application.Nanomaterial modification is an effective method to improve the wear resistance of PTFE.Silicon nitride(Si_(3)N_(4))has high strength and low-friction-coefficient properties,which can overcome the poor wear resistance of PTFE.With modified Si_(3)N_(4) and PTFE as raw materials and polyamideimide(PAI)as binder,the PTFE/Si_(3)N_(4) composite coating is prepared by spraying-curing method,and the tribological properties of the coating are investigated.The structure of Si_(3)N_(4) nanoparticles before and after modification is characterized using scanning electron microscope(SEM)and fourier transform infrared spectroscopy(FT-IR).In addition,the hardness and tribological behavior of the coating are also studied by microhardness tester and friction and wear tester.The results show that KH-570 has been successfully grafted on the surface of Si_(3)N_(4) nanoparticles,and the surface of modified Si_(3)N_(4) nanoparticles becomes rougher,which is benefit for the dispersion of Si_(3)N_(4) nanoparticles.Besides,Si_(3)N_(4) nanoparticles can improve the hardness and tribological properties of the PTFE composite coating.When the mass fraction of modified Si_(3)N_(4) nanoparticles is 1%,the coating achieves the highest hardness(11.1HV)among the samples.And the friction coefficient and wear rate are 0.0755 and 3.78×10^(-3) m^(3)·N^(-1)·m^(-1) respectively,which is the lowest friction coefficient and wear rate among the samples.At this time,the wear mechanism of the coating is mainly abrasive wear.However,when too much modified Si_(3)N_(4) nanoparticles is added,the serious agglomeration occurs,which will reduce the tribological properties of the coating.

关 键 词：氮化硅 聚四氟乙烯 摩擦系数 磨损率 

分 类 号：TQ325.4[化学工程—合成树脂塑料工业] TB383[一般工业技术—材料科学与工程]