Preparation and properties of Al₂O₃/WC-10Co/ZrO₂ cermets

Al₂O₃/WC-10Co/ZrO₂ cermets were prepared by a hot-pressing process by using WC 10Co nanocomposite powder, Y₂O₃ stabilized nanocrystalline ZrO₂ powder and submicron Al₂O₃ powder. The influences of sintering temperature on the microstructure, grain size and properties were investigated according to the density, fracture toughness, Rockwell A hardness (HRA), hysteresis loops and scanning electron microscopy (SEM) micrographs of fractured surfaces of the specimens. The results show that the composite powders (WC-10Co (50%)/Al₂O₃(40%)/ZrO₂(10%)) after being high-energy ball-milled for 48 h was hot-pressing sintered at 1450℃ then submicron Al₂O₃/WC-10Co/ZrO₂ cermets with an average grain size of less than 1μm and better properties of 97.5% in relative density, 7. 446 8 Ma·m^1/2 in fracture toughness, HRA 94.0 is achieved.