Study on preparation and properties of WC-8Co cemented carbide doped with rare earth oxide

Abstract This paper introduced a new way to prepare WC-8Co cemented carbide doped with rare earth oxide that Y2O3/ZrO2 was doped into powders by the wet chemical method and the alloys were densified by hot-pressing sintering. The microstructure of the powders and alloys was characterized by scanning electron microscopy and transmission electron microscopy whereas phase composition was analyzed by X-ray diffraction and energy-dispersive spectroscopy. The density, hardness, and transverse rupture strength (TRS) of the alloys were also tested. Results showed that the addition of Y2O3/ZrO2 refined the WC grains and reaction between Y2O3 and ZrO2 generated new second phase particle of Y4Zr3O12 in the alloy with co-doping of Y2O3 and ZrO2. The carbon content affected the porosity of WC-8Co-Y2O3/ZrO2, and the number of pores reduced with the increase in carbon content. Moreover, the carbon-deficient phase was generated at a low carbon content. When the carbon content was 6.15 wt%, the WC-8Co-Y2O3/ZrO2 alloys achieved the best comprehensive properties.