Densification behavior, microstructure evolution and mechanical properties of Ti(C, N)-based cermets fabricated by in situ carbothermal reduction of WO3 and subsequent liquid sintering

Ti(C, N)-based cermets were successfully fabricated by in situ carbothermal reduction of WO3 and subsequent liquid sintering in one heating process. The densification behavior, phase formation and microstructure evolution of the cermets were investigated by DSC, XRD, SEM, TEM, etc. The results revealed that near fully dense Ti(C, N)-based cermets could be obtained by the above-mentioned method. The addition of WO3, together with higher carbon content, not only reduced the size of carbonitride grains but also improved the flow capacity of the liquid binder and resulted in a more uniform binder layer between the fine ceramic gains. In addition, a new orientation relationship of (1¯11¯)B//(200)R with partially coherent state was observed at the interfaces between the ceramic grains and binder phase. The prepared Ti(C, N)-based cermet showed excellent comprehensive mechanical properties with a transverse rupture strength of 2687 MPa, a Rockwell hardness of 88.7HRA and a fracture toughness of 20.5 MPa·m1/2, respectively.