Study on the Friction and Wear Performance of Graphene/Porous Bronze Composites

The porous surface of air bearings may suffer from surface scratching and wear issues during the start–stop processes or under extreme working conditions. To improve the lubrication performance and service life of the porous restrictors, this study combined powder metallurgy and chemical vapor deposition to fabricate graphene/porous bronze composites. On this basis, the friction and wear properties of porous composites were investigated. The prepared porous composites and the friction surfaces were described by various means such as coefficient of friction (COF), morphology scanning, surface roughness, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Moreover, during the composite fabrication, the flowrates of carbon sources were set to be 3, 6, 9, and 12 sccm, respectively, to investigate the effect of graphene content on the lubrication performance of the original porous matrix. In the experiments, the lubricating performance of the composite was optimized at a flowrate of 12 sccm. Compared to the original porous bronze, the COF was decreased by 8.4% and the wear-rate by 10.5%. Furthermore, the research findings indicated that the grown graphene also affects the sintering process of the porous matrix, leading to weak connections between powders and differences in the final pore structure. Thus, the final pore structure, along with the presence of graphene, jointly influences the lubrication performance of the porous composites.