Preparation And Properties Of Self-Lubricating PTFE Fiber Fabric

With the development of industrial technology,more complex and harsh working conditions put forward higher requirements for the lubrication effect of bearings.Polytetrafluoroethylene(PTFE)fabric reinforced composite is a new kind of solid selflubricating material.PTFE fabrics retain good lubrication properties of PTFE fibers and have better mechanical strength when blended with other high-strength fibers.Therefore,PTFE fiber fabric composites,as the lubricating layer between the inner and outer rings of joint bearings,are widely used in aviation,automobile and other fields.In this paper,the preparation and properties of PTFE fabric reinforced composites were studied.The synthetic material of this experiment is polytetrafluoroethylene fiber and aramid fiber.The two kinds of fibers are woven together by machine knitting machine.After knitting,some of the fabrics were modified by plasma on one side.The fabrics were bonded to metal matrix with 50% wear-resistant epoxy adhesive.The tribological properties of the fabrics were studied by friction and wear testing machine.The wear width of the fabrics was studied by ultra-depth-of-field microscopy.The wear morphology of the surface of the fabrics was observed by scanning electron microscopy.Analysis of wear mechanism.The experimental results show that the higher the applied load is,the smaller the friction coefficient of the untreated composites is,and the smaller the fluctuation of the friction curve tends to be gentle.However,with the increase of friction speed,the friction coefficient of the material increases obviously,and the instability of the friction curve increases with time.After chemical reagent modification,the friction coefficient decreases obviously under low friction load or high friction speed.The experimental data show that plasma surface treatment can protect PTFE film and enhance the bonding between PTFE transfer film and Kevlar fiber surface.Therefore,the PTFE transfer film remains intact with the increase of rotational speed.Surface treatment enhances the stability of friction properties.The wear of fabrics increases with the increase of friction speed and load.After a long time of friction under different friction conditions,most PTFE films of low load and low speed friction fabrics remain intact.Kevlar part is bare but not broken.The wear mode is adhesive wear.With the increase of friction load and rotational speed,PTFE film breaks gradually,and more and more Kevlar fibers are exposed and broken.At this time,the wear mode of fabrics becomes abrasive wear.