Abstract: Effect of Mo and Mo2C on the microstructure and properties of Ti(C,N)-based cermets was investigated in this article. The results have indicated that the weight percentage of Mo from 5 to 10 can reduce Ti(C,N) grain diameter and thickness of the rim, and Ti(C,N) grain can be wetted by Ni-Cu-Mo liquid so as to get small contiguity of Ti(C,N) grain. In that way, the transverse rupture strength of Ti(C,N)-based cermets has reached 1800—1900 MPa; the fracture toughness has been due to 16—18 MPa m1/2. But 15wt pct Mo was not more effective on Ti(C,N)-based cermets, because the thickness of the rim becomes larger. In the circumstance of Mo 2 C, 5 wt pct Mo 2 C was good for microstructure and properties of Ti(C,N)-based cermets, but 11 wt pct Mo 2 C has resulted in larger contiguity of Ti(C,N) grain and big Ti(C,N) grain diameter so as to reduce transverse rupture strength and fracture toughness. So that, the effect of Mo on Ti(C,N)-based cermets is better than Mo 2 C.

Key words: Transverse rupture strength (TRS), Contiguity, Fracture toughness