Microstructural, mechanical and tribological performances of carbon fiber reinforced copper/carbon composites

Two kinds of carbon fiber reinforced copper/carbon composites were fabricated for new carbon based pantograph strip via chemical vapor deposition and impregnation/carbonization technologies. Morphology, conductivity, mechanical, tribological performances of the composites were investigated and compared with those of the pure carbon strip used in China's high-speed railways. Fracture and wear mechanisms were analyzed by probing the failure surface using SEM, 3D profile and physical models. The results reveal that copper mesh-carbon/carbon (C/C) composite and copper foam-C/C composite have more advantages than pure carbon strip in electric conductivity, compact strength and wear resistance. Carbon fiber will bear failure energy and block crack growth during the impact and current-carrying friction tests, thereby improving mechanical strength and wear resistance. Short-cutting carbon fibers with random distribution are not easy to scratch wear surface of friction pair, which is favorable to the formation of a smooth tribolayer for copper foam-C/C composite.