The microstructure of deposited layer in TiC-Mo₂C-Ni cermet which was CVD-coated with titanium carbide under the nearly same conditions as in the case of the coating of WC-Co cemented carbides, in particular the microstructure of the phases containing Ni which was incorporated into the layer, was investigated.
It was made clear that the Ni incorporated in the layer existed in the form of NiTi and Ni₃Ti compounds. The micropores were formed in both the coated layer and the substrate near the interface, accompanied with the formation of those compounds. The incorporation of Ni or the formation of the compounds in the layer would be understood by taking into consideration the fact that the carbon content of titanium carbide deposited on TiC-Mo₂C-Ni cermet was much lower than the stoichiometric value, and also by assuming that the compounds were relatively unstable.