Effect of HfC addition on microstructure of Ti(CN)-Ni cermet system

Ti(CN) based cermets have a core/shell microstructure, which gives rise to outstanding mechanical properties and chemical stability for cutting tool applications. The HfC content and C/N ratio in Ti(C1-xNx) were varied in order to investigate the effect of HfC addition on the microstructure of Ti(C1-xNx)-Ni systems. The presence of HfC in the solid solution, (Ti,Hf)C, was found to cause the surface energy to be more anisotropic in the presence of liquid Ni. A phase separation of (Ti,Hf)C and (Hf,Ti)C was noted when >20wt-%HfC was added to TiC-HfC-Ni. In addition, the Ti(C0.3N0.7) based system showed the lowest coarsening for all sintering times of the various Ti(C1-xNx) systems examined. This study focuses on the role of various Ti(CN) and HfC cermets and how they affect the coarsening of microstructures.