Hardness and wear resistance of carbon nanotube reinforced Cu matrix nanocomposites

Carbon nanotube (CNT) reinforced Cu matrix (CNT/Cu) nanocomposites are fabricated by a novel fabrication process, named as molecular level process, which involves suspending CNTs in solvent by surface functionalization, mixing Cu ions with CNT suspension, drying, calcination and reduction. The molecular level process produces CNT/Cu nanocomposite powders, in which the CNTs are homogeneously implanted within Cu powders. The nanocomposite powders are consolidated into CNT/Cu nanocomposites by spark plasma sintering. The hardness and sliding wear resistance of CNT/Cu nanocomposite are enhanced by two and three times, respectively, compared to those of Cu matrix. The enhancement of hardness is due to the effect of homogeneous distribution of CNTs in Cu matrix, good bonding at CNT/Cu interfaces and high relative density of nanocomposites. The dispersed CNTs in Cu-matrix nanocomposite gives significantly enhanced wear resistance by retarding the peeling of Cu grains during sliding wear process.