Synthesis and characterization of extremely hard and strong (W,Ti,Ta)C cermet by spark plasma sintering

In this study, spark plasma sintering (SPS) technology was used to prepare (W,Ti,Ta)C cermet. The mechanical properties and microstructure of the (W,Ti,Ta)C cermet under different sintering temperatures, holding times, and sintering pressures were studied by orthogonal experiments, and optimal sintering parameters were obtained. The results show that under a sintering temperature of 1400 °C, holding time of 10 min, and sintering pressure of 30 MPa, the grain size of the cermet was uniform, the relative density was higher, and the mechanical properties were optimal. The Vickers hardness and flexural strength of the cermet were 20.39 ± 0.3 GPa and 1389 ± 35 MPa, respectively. Solid solution strengthening at the grain boundary was shown to improve the interfacial bonding force of the cermet, which is the main reason for the improved flexural strength and fracture toughness of the (W,Ti,Ta)C cermet. • The sintering parameters of (W, Ti, Ta)C cermet prepared by SPS were analyzed by orthogonal experiment, and its mechanical properties were tested.The sintering parameters of (W, Ti, Ta)C cermet prepared by SPS were analyzed by orthogonal. • Under the optimal sintering parameters, the grains combine closely, the grain size is uniform, and no abnormal growth of grains. • The high strength and high hardness of (W, Ti, Ta)C cermet are mainly due to the topologically-oriented conjunctive structure formed by grain boundaries. • The main crack propagation modes of (W, Ti, Ta)C cermet are crack deflection and crack bridging, which are important ways to improve mechanical properties.