Effect of Salinity on Friction Properties of PTFE/Kevlar Fabric Composites

Self-lubricating spherical plain bearings are widely used in some important mechanical moving parts. When used in the marine environment, bearing components may be sometimes immersed by seawater. The salinity changes with evaporation or addition of water. This paper discusses the effects of salinity on the friction properties of PTFE/Kevlar fabric composites. Four different salinities seawater were formulated. The friction test was carried out on MMU-5G friction and wear testing machine under seawater. The worn surface morphology was observed by Confocal Laser Scanning Microscopy (CLSM). The result shows that the salinity of seawater has an obvious influence on the friction and wear performance of PTFE/Kevlar fabric composites. The steady-state friction coefficient decreases with the salinity increasing under load 20 MPa, velocity 0.2 m/s. The wear rates increase with the slide velocity increasing. The suitable salinities range for PTFE/Kevlar fabric composites used in seawater is 3%similar to 5%. The mechano-electrochemical interactions and abrasive wear play an important role in the wear of PTFE/Kevlar fabric composites.