Ultrafine (Ti, M)(C, N)-based cermets with optimal mechanical properties

A tough and strong cermet with the composition (Ti,20M,0.2V)(C,N)-16M-20Ni/Co (M = W,Mo) was prepared by mixing WC and Mo2C with ultrafine (Ti,M)(C,N) powders, and then, processed via a conventional P/M technique. It has an ultrafine and distinct core/rim structure, resulting in excellent mechanical properties: bending strength of 2210 MPa, HV hardness of 14.7 GPa and toughness of 10.1 MPa m1/2. The small concentration gradient in core/rim composition and the disappearance of inner rims benefit the reduction of the stress concentration at the core/rim interface in (Ti,M)(C,N)-MxC cermets, and thus improve their toughness. In addition, ultrafine microstrucure improves mainly their bending strength and hardness.