The Effenct of Sintering Temperatures on Microstructures and Mechanical Properties of WC-Co-Ti3SiC2 Cemented Carbides

Abstract:

Taking the WC-Co-Ti3SiC2 cemented carbide dropped with 3.0wt.% Ti3SiC2 as the case, the effect of sintering temperatures (1350~1470 oC) on the microstructure, density and mechanical properties of WC-Co-Ti3SiC2 cemented carbide were investigated. The results show that as sintering temperatures increase, the fractions of decomposed Ti3SiC2 as well as volume fractions of (W,Ti)C and WSi2 phases in as-received WC-Co-Ti3SiC2 cemented carbides gradually increase. Meanwhile, the increase of sintering temperature results in the increase of the WC mean grain size. The hardness of WC-Co-Ti3SiC2 cemented carbides increases and then decreases with the increase of sintering temperature, while the fracture toughness decreases gradually. When the sintering temperature is 1410 oC, the density of WC-Co-Ti3SiC2 is optimum, and the porosity is 0.47 %. Meanwhile, the 1410 oC is optimum sintering temperature for the mechanical properties of WC-Co-Ti3SiC2 cemented carbides. The hardness and fracture toughness are 2076.36 kgf/mm2 and 10.15 MPa·m1/2, respectively. The enhancement in hardness is attributed to the increase in density of cemented carbides, while the reduction in fracture toughness result from the increase in the content of brittle phases (W,Ti)C and WSi2 in the cemented carbide.