Optimizing the Tribological Performance of Graphite-Resin Composites: The Role of High Crystallinity, Nano Morphology, and Hydrophobic Surface Modification.

Graphite, with its layered structure and weak van der Waals bonding between graphene nano layers, exhibits excellent self-lubricating properties. Natural graphite, characterized by high crystallinity, and artificial graphite, with relatively low crystallinity, exhibit distinct friction behaviors and structural differences, which significantly influence the performance of graphite-resin composites as solid lubricants. This study investigates the effects of natural/artificial graphite ratios and hydrophobic silane coupling treatment on the oil impregnation behavior, friction coefficient, wear stability, and microstructural changes in graphite-resin composites. Under a vertical load of 88,260 N and surface pressure of 50 MPa, the impregnated graphite-resin composites demonstrated low friction coefficients and stable wear behavior. SEM analysis revealed well-preserved microstructures, and Raman spectroscopy confirmed the formation of stable lubrication films through the ID/IG ratio, indicating graphene exfoliation. The results indicate that natural graphite provides dense structures and stable friction, while artificial graphite enhances oil impregnation but leads to unstable friction behavior.