Tribological properties of carbon nanotube-reinforced composites

The friction and wear behavior of fiber-reinforced composites is dependent on fabrication, operational, and environmental parameters. In particular, the type of fibers employed seems to have crucial influence. Carbon nanotubes (CNTs), discovered less than 20 years ago, aroused big enthusiasm around the world because of their excellent properties and potential application in many fields. Compared with carbon fibers, CNTs possess ultrahigh strength, modulus and perfect graphite layered structure, which imply their promising application as wearable materials in tribological fields. Friction and wear test results suggest that, compared with carbon fiber-reinforced composites, composites with CNTs as reinforcing elements exhibit more stable frictional coefficient and lower wear rates, especially at high temperatures. Based on experimental results conducted on epoxy resin and carbon matrix composites, two possible mechanisms about friction and wear process are proposed. In addition, some potential tribological applications of CNT-reinforced composites are discussed in brief.