Friction and Wear Behaviors of PEEK/h-BN/SCF Composites Under Dry and Starved Oil Lubrications

The incorporation of various types of fillers is critical to enhancing the starved oil lubrication performance of PEEK matrix composites. In this work, PEEK composites reinforced with h-BN and SCFs were fabricated via a hot-pressing method, and the friction and wear behaviors under dry sliding and starved oil lubrication were systematically investigated. Surface oil wettability and Vickers hardness were characterized, and tribological tests were conducted on a ball-on-disk reciprocating tribometer. Worn surface topography and wear mechanisms were elucidated through laser scanning confocal microscopy and scanning electron microscopy. The results show that h-BN effectively reduces the friction coefficient through its solid lubrication effect, while SCFs significantly improve the hardness and load-bearing capacity of the PEEK matrix. Under dry sliding conditions, the PEEK composite containing h-BN and SCFs achieves the lowest wear rate of 10.3 × 10^-5 mm³/(N·m), which is 74.6% lower than that of pure PEEK, indicating a synergistic anti-wear effect. Under starved oil lubrication, PEEK/h-BN maintains the smoothest and lowest friction, and the presence of SCFs further improves wear resistance of PEEK composites despite a slight increase in friction. In addition, the fillers' incorporation reduces the surface oil wettability of the PEEK composites; the dominant wear mechanism hence transforms from severe adhesive wear and plastic deformation in pure PEEK to mild abrasive wear.