Microstructure and tribological properties of in-situ TiC-C/Cu nanocomposites synthesized using different carbon sources (graphite, carbon nanotube and graphene) in the Cu-Ti-C system

For the first time, TiC-C/Cu nanocomposites were fabricated from a mixture of Cu, Ti and C powders by the use of different carbon sources (graphite, carbon nanotube (CNT) and graphene) through two-step high energy mechanical milling and in-situ synthesis by annealing, to study the effect of carbon source on phases formation and tribological properties. The results showed the presence of Cu as the matrix, TiC and unreacted carbon phases in the microstructure of sintered samples, and relatively uniform distribution of the reinforcement phase in the copper matrix was obtained. With the decrease of carbon source size, the density of sintered nano-composites was reduced. It was revealed that using the CNT and graphene as carbon sources results in finer TiC nanoparticles, which considerably improves the tribological properties of the nanocomposite. Using CNT and graphene as carbon sources led to 15% and 49% reduction in wear volume loss and 16% and 6% decrease in friction coefficient respectively, in compassion to using graphite.