Effect of Sintering Temperature on Microstructure and Mechanical Properties of WC-Co-Ti3SiC2 Cemented Carbides

Taking the WC- Co-Ti3SiC2 cemented carbide doped with 3.0wt% Ti3SiC2 as the case, the effect of sintering temperature (1350 similar to 1470 degrees C) on the microstructure, relative density, and mechanical properties of WC-Co-Ti3SiC2 cemented carbide was investigated. The results show that with increasing the sintering temperatures, the fraction of decomposed Ti3SiC2 is increased and the generation of (W, Ti)C and WSi2 phases is promoted in as-received WC-Co-Ti3SiC2 cemented carbides. Meanwhile, the increase in sintering temperature also results in the increase in WC mean grain size. The hardness of WC-Co-Ti3SiC2 cemented carbides is increased and then decreased with increasing the sintering temperature, and the fracture toughness decreases gradually. When the sintering temperature is 1410 degrees C, the relative density of WC-Co-Ti3SiC2 is optimum, and the porosity is 0.47%. Meanwhile, 1410 degrees C is the optimum sintering temperature to achieve the optimal mechanical properties of WC- Co-Ti3SiC2 cemented carbides. The hardness and fracture toughness are 20 348.328 MPa and 10.15 MPa center dot m(1/2), respectively. The improvement in hardness is attributed to the relative density increase in cemented carbides, while the reduction of fracture toughness results from the increase in brittle phases ( W, Ti)C and WSi2.