MICROSTRUCTURAL EVOLUTION DURING THE SINTERING OF TIC-MO-NI CERMETS

TiC-Ni-Mo cermet specimens were prepared by using a mixture of fine (1.5 mum) and coarse (30 mum) TiC powders. When the fraction of fine TiC particles was 80%, a (Ti,Mo,Ni)C complex carbide phase was observed deposited on the coarse TiC particles and resulted in a typical cored structure. As the fraction of fine TiC particles decreased, the coarse TiC particles exhibited a unique microstructural evolution with the development of a concave interface. This microstructural change of the coarse TiC grains can be explained in terms of the coherency strain energy.