THE INFLUENCE OF OXIDATION OF THE FIBERS ON THE TRIBOLOGICAL PROPERTIES OF CARBON FIBER-REINFORCED NYLON COMPOSITES

Three-dimensional braided carbon fiber-reinforced nylon composites (C_3D/MCN) were prepared in order to investigate the influence of oxidation of carbon fibers on the tribological properties of the C_3D/MCN composites. Friction and wear tests of the C_3D/MCN composites with untreated and treated carbon fabric were conducted. The characteristics of the carbon fiber, the interface strength, the hardness, and the worn surface morphologies of the C_3D/MCN composites were analyzed. The results show that the specific surface area of treated carbon fiber was far higher than that of untreated carbon fiber and there formed a functional group of –C=O on the carbon fiber surface after air oxidation. The oxidation of the carbon fibers improved the interface strength between the carbon fibers and the matrix and had little effect on the hardness of the composites. The friction coefficient and wear rate of C_3D/MCN composites with oxidized carbon fibers were apparently lower than those with untreated carbon fibers. In conclusion, the oxidation of the fibers showed good effects on the improvement of the interface strength and the tribological properties of the composites.