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A novel method is proposed to chemically graft 3-aminopropyltriethoxysilane (APS) onto the MnO2 nanosheets which grown on woven carbon fiber (WCF), forming the CF-MnO2-APS hierachical reinforcement, as confirmed by FTIR, EDS and XPS. The flexural and tensile strength of corresponding composite are 150.4 MPa and 292.3 MPa, for an increase of 46.9% and 31.7%, respectively. Besides, the composite displays the optimal anti-wear under various applied load. Our work finds that grafting APS onto MnO2 nanosheets is the major reason for forming chemical bonding at fiber/matrix interface. Overall, the synergetic effects of mechanical interlocking and chemical bonding at interface are primary in improving the comprehensive properties of composites.

The TiO2 nanowires/TiO2 film/woven carbon fiber ternary hybrid was prepared through hydrothermal, following the formation of TiO2 film on carbon fiber, to improve the mechanical and wear-resisting property of woven carbon fiber reinforced phenolic composite. The TiO2 film between carbon fiber and TiO2 nanowires offered a stable interface among ternary hybrid and resin matrix. Composite reinforced by the ternary hybrid displayed significant bending strength and stability frictional behavior. Moreover, the wear rate for resulted composite reflected a 60.8% decrease under 8 N, compared to that of the desized-woven carbon fiber reinforced composite. The promoted anti-wear property was mainly attributed to the improved ternary hybrid/matrix interface and optimized stress dispersion.

In order to improve the friction and wear properties of the paper-based friction materials, SiC particles (SiCp) were uniformly deposited onto the paper-based friction material via electrophoretic deposition with 300 V, 400 V and 500 V deposition voltages, obtaining the SiCp-content of 10.8, 15.9 and 22.9 wt%. The microstructure and thermal stability of the paper-based friction materials were characterized by scanning electron microscope (SEM) and thermogravimetry (TG). And the porosity, mechanical and tribological properties of samples were tested by mercury injection apparatus, electromechanical universal testing machine and friction tester. The results show that the uniform distribution of SiCp in the paper-based friction materials decreases the porosity and obviously improves the thermal stability and mechanical properties. Meanwhile, the incorporation of SiCp increases the stability of friction coefficient and the wear resistance of paper-based friction materials. Especially, the wear rate of paper-based friction material with 400 V deposition voltage treatment (CP400) for optimal SiCp-content of 15.9% decreases by 51.2% from 5.8 × 10−14 to 2.8 × 10−14 m3/(N·m) compared with that of the bare paper-based friction material (CP0). The electrophoretic deposition techniques provide the possibility of uniform addition of micro-nano particles to the paper-based friction material, which is beneficial to improve the friction and wear properties.

In order to synthetically evaluate the tribological properties of friction materials, fuzzy comprehensive evaluation model was developed. The analytic hierarchy process was introduced into the model to establish weight function. The paper-based friction materials with different CNTs content were chosen as the six projects. It is found that the comprehensive evaluation indexes are increased by 126–307% for the samples with 4–15 wt% of CNTs compared with the sample without CNTs. The judgment matrix has high consistency by consistency checking. And the evaluation results are also in accordance with the results obtained through the friction torque, surface structure and temperature.

Four kinds of paper-based friction materials reinforced with carbon fibers of 100, 400, 600 and 800 μm were prepared by paper-making processes. Experimental results showed that the friction materials became porous with fiber length increasing. The friction torque curves were flat except the sample with 100 μm fibers. The wear rate of the sample with 100 μm fibers was only 1.40×10−5 mm3/J. Tiny debris and fine scratches formed in the worn surface were the reason for excellent wear resistance of friction pairs with 100 μm fibers. The friction pairs with 400, 600 and 800 μm fibers showed typically abrasive wear and fatigue wear.

Four kinds of carbon fabric reinforced phenolic resin composites were fabricated by the impregnation technique in the present study. And the effect of phenolic resin on friction and wear performance of the composites was investigated. Experimental results showed that the friction torque curves of the samples were very flat during the mixed asperity contact phase of the engagement except the sample with 30 wt% resin content. The dynamic friction coefficient ( μ d ) decreased with the increase of resin content, but the friction coefficient ratio increased. The wear rates of all samples did not exceed 1.30×10 −5 mm 3 /J, indicating excellent wear resistance of carbon fabric/phenolic composites. Meanwhile the composites were very friendly to the couple plate. The sample with 25 wt% resin content possessed the best wear resistance due to the moderated combination between the carbon fibers and the matrix and good friction surface formation.