Impact of pv Values on the Friction and Wear Performance of Blended Fiber Composite Materials

As the key factor affecting the friction and wear properties of PTFE (polytetrafluoroethylene) blended fibers, the product pv value of applied load and sliding velocity was studied in this paper, two blended fiber composites, GF/PTFE (glass fiber/ polytetrafluoroethylene fiber) and Kevlar/PTFE (Kevlar fiber/polytetrafluoroethylene fiber), and based on its working conditions, Friction and wear tests were conducted on the HLR-7000 reciprocating friction and wear tester with pv value as the variable. To explore their friction and wear properties and wear mechanism changes at different pv values. The results demonstrated that at a pv value of 2.4 MPa·m/s, the friction coefficient of the GF/PTFE blended fiber composite material was lower than that of the Kevlar/PTFE blended fiber composite material. Furthermore, the wear mechanisms differed between the two materials. The GF/PTFE blended fiber composite material exhibited a lower wear volume, with wear predominantly characterized by abrasive wear and accompanied by minor fatigue wear. Conversely, the Kevlar/PTFE blended fiber composite material showed a higher wear volume, with wear primarily driven by fatigue wear. At a pv value of 4.8 MPa·m/s, both materials were predominantly subjected to abrasive wear; however, the GF/PTFE blended fiber composite material experienced more severe surface damage and a higher wear volume. Microscopic analysis using an optical microscope, scanning electron microscope (SEM), and energy-dispersive spectrometer (EDS) was conducted on the initial and worn surface morphology, wear debris, transfer film, and elemental distribution of the samples, revealed that at a pv value of 4.8 MPa·m/s, there was a significant increase in the content of fluorine elements within the wear track area, which was more uniformly distributed, contributing to a more continuous formation of the transfer film on the rubbing surface. Under conditions of a pv value of 2.4 MPa·m/s, the performance of the GF/PTFE blended fiber composite material was superior to that of the Kevlar/PTFE blended fiber composite material. In contrast, under conditions of a pv value of 4.8 MPa·m/s, the Kevlar/PTFE blended fiber composite material exhibited superior wear resistance.