Synthesis of Y2O3-doped WC-Co powders by wet chemical method and its effect on the properties of WC-Co cemented carbide alloy

WC-8Co composite powders doped with Y2O3 were prepared by wet chemical method, and the densification of alloy proceeded by spark plasma sintering at 1200 °C, 1250 °C, and 1300 °C. The microstructure of the composite powders and alloys was analyzed by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and high-resolution transmission electron microscopy. Result showed that the addition of Y2O3 could refine WC particles during carbonization and WC grains during sintering. In the microstructure of WC-Co alloys, Y2O3 solidly dissolved in the body of WC crystal with the form of the second-phase nanocrystal. Moreover, the effect of sintering temperature on WC-8Co cemented carbide doped with Y2O3 was studied. The comprehensive performance of WC-8Co cemented carbide doped with Y2O3 was best at the sintering temperature of 1250 °C with the hardness of 19.64 GPa and fracture toughness of 11.97 MPa m1/2.