Microwave sintering of Al2O3-ZrO2-WC-Co cermets

Composite powders of nanocrystalline WC-10Co (15wt%), Y₂O₃ (8mol%) stabilized nanocrystalline ZrO₂ (30wt%), industrial cobalt powder (4.5wt%) and submicron Al₂O₃ (55wt%) composite powders were fabricated by high-energy ball-milling process. The nanocomposite powders were consolidated by microwave sintering process at temperature ranged 1300 °C–1550 °C for 15 min, respectively. The optimum consolidation conditions, such as temperature, were researched during microwave sintering process. Vickers Hardness of the consolidated cermets was measured by using a Vickers indentation test, and density of specimens was also determined by Archimedes’ principle. Microwave sintering process could not only increase the density of Al₂O₃-ZrO₂-WC-Co cermets and reduce the porosity, but also inhibit abnormal grain growth.