Tribological Behavior of in Situ Processed Ni-Ti-C Nanocomposites

Ni-Ti-C metal matrix composites (MMCs) with in situ formed, homogeneously distributed titanium carbide (TiC), as well as graphite (C) reinforcement in the nickel metal matrix, were synthesized using mechanical alloying (MA) followed by spark plasma sintering (SPS). The main objective of this research is to consolidate Ni-Ti-C MMCs with varying C/Ti ratio and characterize the MMCs to investigate the altered mechanical and tribological behavior in comparison with pure nickel. Experimental results showed that these composites possess a refined microstructure in addition to the presence of hard TiC precipitates within the nickel matrix. Additionally, by tailoring the C/Ti ratio in these composites, an additional graphitic phase is engineered into the microstructure. All Ni-Ti-C nanocomposites exhibited excellent microhardness as well as enhanced tribological performance compared to pure nickel. The increased mechanical properties are primarily attributed to the presence of in situ formed nanoscopic TiC and graphite reinforcing the nickel matrix.