Interface construction of micro/nano hierarchical structure to enhance the tribological performance of carbon fabric/phenolic composite

Carbon fabric (CF)/polymer composites are potential lubricating materials, which could be used for plane bearing lining, sliding guide rails, and other moving parts of advanced equipment. But the low bonding strength at the interface between the carbon fibers and the polymer matrix is a great challenge to developing high-performance CF/polymer composites. In this study, the CF is coated with an active transition layer using high-adhesion polydopamine (PDA) as an ideal plate for the TiO2 micro/nano hierarchical structure to construct CF-PDA-TiO2. This hierarchical structure is made of micro-bundles, each composed of numerous nanorods, and decorated on CF surface densely and uniformly. The interfacial combination of CF-PDA-TiO2 and phenolic resin (PF) shows excellent performance, and the interlaminar shear strength (ILSS) of CF-PDA-TiO2/PF is improved from 10.48 MPa to 37.22 MPa, attributed to the improved interfacial physicochemical interaction. Furthermore, the tribological performance of CF-PDA-TiO2/PF with size of Φ30 mm✕5 mm is characterized by sliding against 440C stainless steel ball with diameter of 8 mm using ball-on-disc sliding wear tester (MPX-3). The tribological results demonstrate that the friction coefficient and wear rate of CF-PDA-TiO2/PF are reduced by 37.91% and 77.6%, compared to CF/PF. Moreover, the CF-PDA-TiO2/PF maintains low friction coefficient and wear rate under high-load and high-speed sliding conditions. This is mainly because TiO2 nanorod bundles exhibit micro/nano multi-scale interfacial enhancement, promoting stress distribution and micro-cracks deflection etc. Moreover, TiO2 nanorod bundles could promote the formation of a uniform transfer film to decrease friction and wear. This work implies that interface construction of micro/nano hierarchical structure is a promising way to enhance the tribological performance of CF/polymer composites.