Mechanical properties and microstructure of Ti(C,N) based cermets reinforced by nano-Si3N4 particles

Titanium carbonitride (Ti(C,N)) matrix cermets with different contents of nano-Si3N4 particles have been fabricated by microwave sintering in nitrogen atmosphere. The addition of nano-Si3N4 particle has important effect on the property of this cermet. Hardness and transverse rupture strength of the cermet are improved to about 1.3% and 25.2%, respectively, when the content of nano-particles is 2.0% in weight. Scanning electron microscopy (SEM) in combination with energy dispersive X-ray analysis (EDX) reveals that various cermets with or without nano-Si3N4 present quite different morphological and structural characteristics. It may be because that the addition of nano-Si3N4 particles inhibits the dissolution of Ti(C,N), and promotes the dissolution of WC and Mo2C in binder phase and the formation of the inner rim. The modified microstructure by the addition of nano-Si3N4 particles results in the high mechanical properties of the cermet.