Abstract:In order to improve the vibration and noise reduction performance of thermoplastic polyurethane (TPU),a water lubricated bearing material,PTFE/TPU modified composite material was prepared by physical blending using TPU as the matrix and polytetrafluoroethylene (PTFE) as an additive.By simulating sediment conditions on an RTEC friction and wear testing machine,tribological tests of PTFE/TPU modified composite material were conducted at different speeds and loads.By analyzing the mechanical properties,friction coefficient,surface morphology,and vibration noise behavior of composite materials,the friction and wear laws and vibration and noise reduction performance of composite materials were explored.The results show that the tensile strength and Shore hardness of the composite material first increase and then decrease with the increase of PTFE content,and the TPU composite material with 8% mass fraction of PTFE exhibits the best mechanical properties.As the speed and load increase,the friction coefficient of composite materials gradually increases,and serious damage such as surface damage,deformation,and peeling gradually increase.Compared with pure TPU,the friction and wear intensity of modified composite materials is lower,the change in friction coefficient is relatively small and the friction coefficient curve is relatively smooth,and the micro surface damage of the material is less.With the increase of speed and load,the vibration response and radiation noise phenomenon of composite materials increase,the average intensity of vibration and noise signals increases,the frequency component in the frequency domain increases,the amplitude component increases,and the main frequency shifts to high frequency.PTFE can improve the tribological performance of TPU,reduce friction coefficient,and endow composite materials with certain vibration and noise reduction performance,and the effect is more obvious under high-speed and high load conditions.