Mechanical and tribological properties of carbon fabric composites filled with several nano-particulates

The carbon fabric composites filled with the particulates of nano-SiO₂, nano-TiO₂, and nano-CaCO₃, respectively, were prepared by dip-coating of the carbon fabric in a phenolic resin containing the particulates to be incorporated and the successive curing. The friction and wear behaviors of the resulting carbon fabric composites sliding against AISI-1045 steel in a pin-on-disc configuration were evaluated on a Xuanwu-III high temperature friction and wear tester. The tensile strength and adhesion strength of the filled carbon fabric composites were determined on a DY35 universal materials test machine. The morphologies of the worn surfaces of the unfilled and filled carbon fabric composites and the transfer films on the counterpart steel pins were analyzed by means of scanning electron microscopy, and the elemental plane distributions on the transfer films were analyzed with an energy dispersive X-ray analyzer (EDAX). It was found that the nano-particles as the fillers contributed to significantly improve the mechanical properties and wear-resistance of the carbon fabric. Nano-CaCO₃ as the filler was the most effective in increasing the wear-resistance, while nano-SiO₂ was the most effective in increasing the friction-reducing ability and mechanical properties. This was because the nano-particulates as the fillers contributed to enhance the bonding strength between the carbon fabric and the adhesive resin. Moreover, the friction and wear properties of the carbon fabric composites were closely dependent on the characteristics of the transfer films formed on the counterpart steel pin surfaces and on the environmental temperature as well. Namely, the differences in the wear-resistance of various filled carbon fabric composites were related to the differences of their transfer films on the counterpart steel pin surface. The wear rates of the composites at elevated temperature above 180 °C were much larger than that below 180 °C, which was attributed to the degradation and decomposition of the adhesive resin at excessively elevated temperature.