Construction of Fluorinated Nanolayer on Nickel‐Coated Carbon Fiber and Its Enhancement in Tribological Performance of Polytetrafluoroethylene Composites

ABSTRACT Enhancing the interfacial bonding between the polytetrafluoroethylene (PTFE) matrix and inorganic fibers is essential for lubricating composites to serve as bearings, gears, and sealing gaskets. In this study, Ni‐coated carbon fibers (Ni@CF) with high thermal conductivity and mechanical strength were selected as reinforcements for the PTFE matrix, and a fluorinated modification layer containing PTFE nanoparticles and hydrolytic fluoroalkylsilane was fabricated on the Ni@CF surface. The enhancement in lubricating performance of the Ni@CF/PTFE composites through the incorporation of Ni@CF with gradient modification amounts was investigated. The results revealed that a fluorinated layer with a thickness ranging from 2 to 12 nm was modified on the Ni@CF hybrid and filled the asperities of the Ni bulges, generating fibril interlocking with the PTFE matrix. After fluorinated modification, a tensile strength of 31.1 MPa and a break elongation of 393% were obtained for the developed m‐Ni@CF/PTFE composites. As the modification content increases, the wear rate progressively decreases, reaching a minimum value of 7.8 × 10 −6 mm 3 /N·m, which is a 73% reduction compared with that of the Ni@CF/PTFE composites without surface modification.