Processing of TiCN-WC-Ni/Co Cermets via Conventional and Spark Plasma Sintering Technique.

In the present research, the effect of TaC addition as ternary carbide on the microstructure and mechanical properties of dense Ti(CN)-WC-Ni/Co cermets processed via powder metallurgy route by conventional and SPS sintering technique was investigated. XRD patterns of SPS sintered cermets revealed peak broadening confirming evolution of refined carbide size during sintering. Sintered cermets showed Ti(CN) core and (Ti,W)(CN)/(Ti,W,Ta)(CN) rim solid solution. Least contiguity (C) of the ceramic particles and largest mean free path (λ) of the binder phase was observed for the cermet having TaC and Ni-Co addition. Hardness and fracture toughness of the TiCN based cermets prepared via conventional sintering varied from 14-16 GPa and 8.75-9.25 MPa m and via SPS technique varied from 15-17 GPa and 8.79-9.51 MPa m. Nano hardness of different phases varied from 9.83 to 26.01 GPa for sintered cermets. Refined carbide size and least fraction of adjacent ceramic phase resulted in improved properties of TaC added TiCN-WC-Ni/Co cermet. [ABSTRACT FROM AUTHOR]