Study On Dry-sliding Behavior Of Spherical-surface Contact Between Carbon Fiber Composite And Metal

The rise of high-performance carbon fiber composites has shaken the position of metal materials in the field of friction.In the study of the tribological properties of carbon fiber composites,few studies have focused on the formation process and transfer mechanism of the transfer film.Due to the rise of bionics,surface texture technology has been widely used in various fields.However,the effect of surface texturing on the tribological properties of carbon fiber composites has not been studied in details.In this paper,the tribological properties of carbon fiber composites were investigated by carrying out wear tests against the textured and smooth metal materials under dry condition.First,the formation process and transfer mechanism of the transfer film were discussed by carrying out wear tests with carbon fiber/epoxy(CF/EP)composite against iron alloy under dry condition by using a ball-on-disk friction equipment.On the one hand,the changes in the morphology of the worn surface of iron alloy at different friction moments were studied by using scanning electron microscope(SEM)and X-ray photoelectron spectroscopy(XPS).On the other hand,the changes in the morphology of the worn surface of CF/EP at different friction moments were studied by using SEM and energy dispersive X-ray spectrometer(EDS).Results showed that during friction process,not only the softer material(CF/EP)would transfer to the worn surface of the iron alloy to form a resin transfer film(forward transfer);the harder material(iron alloy)would also transfer to the worn surface of CF/EP(backward transfer),forward transfer and backward transfer have occured throughout the friction process.The epoxy resin on the frictional surface of the carbon fiber composite material would peel off,and the peeling of the epoxy resin would promote the material transfer.Due to cyclic loading on the frictional surface of iron alloy,plastic deformation of the frictional surface of the iron alloy occurs,and work hardening occurs in some local areas.In addition,the effect of surface texturing on the tribological behavior was investigated by carrying out wear tests with carbon fiber/polyetheretherketone(CF/PEEK)composites against hard alloy YG8.A single row of circular pit array texture was fabricated on the surface of YG8 by using laser processing technology,and the effect of laser processing parameters onthe geometric characteristics of circular pit was discussed.The effects of different morphological parameters of surface texturing(including the diameter,spacing and depth of circular pits)on the tribological behavior of CF/PEEK,especially on the running-in period,were also investigated.The application of surface texturing makes the friction pair quickly reach a stable status,and reduces the average friction coefficient,indicating that the surface texturing on the surface of YG8 improves the tribological properties of the friction pair between CF/PEEK and YG8.At the same time,the application of surface texturing has an abrasive effect on CF/PEEK,which can be attributed to the micro-cutting effect of circular pit edges on carbon fiber composite materials.