Friction and wear of copper-carbon nanofibers compact composites prepared by chemical vapor deposition

Cu-CNFs compact composites with a CNFs content up to 33 vol% were fabricated out of the powder produced in a one-step CVD process for the purpose of developing a functional material with high electrical and tribological characteristics. The friction coefficient, wear and microstructure of the proposed material were compared to conventional Cu-graphite composites consolidated under the same conditions. The friction coefficient of the Cu-(17-33)vol%CNF was found to be 8 times less than that of pure copper and coincides within experimental error with the Cu-graphite composites. The reduction of the friction coefficient in Cu-CNFs is caused in less extent by squeezed out lubricating carbon debris, as it is in Cu-graphite materials, but by the sliding of very thin wear sheets along the grain boundaries enriched with CNFs. The wear in Cu-33 vol%CNFs material was more than two times less compared to that of Cu-33 vol% graphite samples, which is explained by the delamination of thinner wear sheets.