Effects of metal phases on microstructure and mechanical properties of microwave-sintered Ti(C,N)-based cermet tool

A kind of Ti(C, N)-based cermet tool material was prepared by microwave sintering. The influence of metal phases (Ni, Co, and Mo) on densification and mechanical properties was studied by orthogonal test. The results indicated that Co was more significant in improving relative density and fracture toughness than Ni, while Ni and Co had the similar effects on increasing the hardness of Ti(C, N)-based cermet. Mo can improve fracture toughness but decrease hardness. Ti(C, N)-based cermet with 6 wt% Ni, 6 wt% Co and 6 wt% Mo (TN6C6M6) had the optimal comprehensive mechanical performances, and its fracture toughness and hardness were better than that of Ti(C, N)-based cermet prepared by conventional sintering. The increasing of sintering temperature promoted the uniformity of microstructure and significantly improved densification and hardness of the Ti(C, N)-based cermet. The highest fracture toughness of TN6C6M6 (12.41 ± 0.33 MPa·m^1/2) was achieved when sintered at 1600°C. For the microwave-sintered Ti(C, N)-based cermet, heat preservation period had little effect on densification. The relative density can reach up to 98.6% even though the heat preservation period was 0 minute.