Synergism of hollow MoS₂ nano-particles and WS₂ micro-particles on improving the tribological properties of carbon fiber fabric reinforced phenolic-based composites

The hollow MoS₂ nano-particles were synthesized via hydrothermal method and were used as additives to fabricate the carbon fiber fabric/phenolic composites (CF/PF) containing WS₂ micro-particles by hot-press approach. Subsequently, the tribological properties of CF/PF composites were comprehensively investigated. We found that the addition of WS₂ alone can achieve significant decrease in the friction coefficient of CF/PF composites, but it decreases the wear resistance due to the peeling off of WS₂ micro-particles form matrix caused by stress concentration. Nevertheless, the addition of both WS₂ micro-particles and MoS₂ nano-particles can achieve significant improvement in the lubricating property and wear resistance of CF/PF composites, indicating that there existed a synergetic effect among carbon fibers, WS₂ micro-particles, and MoS₂ nano-particles to enhance the tribological properties of CF/PF composites. The doping of additives with large size range can promote the formation of transfer film on the surface of counterpart as well as enhance the mechanical properties of matrix. Furthermore, the multi-scale additives reduced the stress concentration of matrix around the CF and hence inhibited the breakage, pull-out of CF, resulting in the improvement of the tribological properties due to the high load-carrying capacity of CF.