The Mechanical Performance of In Situ Processed Nickel-Titanium-Graphite Metal Matrix Composites: Influence of Processing Mechanical Alloying and Spark Plasma Sintering

摘要

Nickel-Titanium-Graphite-based metal matrix composites (MMC) with in situ formed titanium carbide (TiC), as well as graphite (C) reinforcement in the nickel (Ni) metal matrix, were processed using mechanical alloying (MA) and spark plasma sintering (SPS). The objective of this study is to synthesize the Ni-Ti-C composites by altering the carbon to titanium ratio and characterize to study its effects on mechanical and tribological behavior as compared with SPS processed pure nickel. Results indicated that these composites exhibit refined microstructure and the homogeneously distributed titanium carbide reinforcement in the nickel matrix. Moreover, by tailoring the carbon to titanium ratio in these composites, an additional graphitic phase is engineered into the microstructure. The steady-state coefficient of friction is obtained for pure nickel and Ni-Ti-C composites. The Ni-Ti-C composites exhibited increment in microhardness, as well as a significant improvement in the tribological behavior as compared to pure nickel.