Microstructure and Mechanical Properties of c-BN Reinforced (Ti,W)C-Based Cermet Tool Materials

(Ti,W)C-based cement tool materials with c-BN particles as additive phase are fabricated by the hot press sintering. The effect of c-BN addition on the microstructure and mechanical properties of (Ti,W)C-based cement tool materials are investigated. With the addition of c-BN, the fracture mode of composite transform from intergranular to transgranular fracture. The main toughening mechanism is particle bridging, crack deflection and crack bifurcation, which improve the fracture toughness of cement tool material. The proper addition of c-BN can improve the mechanical properties of the composites. When the content of c-BN is 1.5 wt %, (Ti,W)C-based cement tool materials reaches the optimum comprehensive mechanical properties. The hardness, the flexural strength and the fracture toughness is 19.78 GPa, 987 MPa and 9.44 MPa m 1/2 , respectively.