Sintering of alumina-mullite-zirconia composites using microwave heating

In this study، the sintering of alumina-mullite-zirconia composites using microwave heating has been examined. Raw materials were alumina and zircon powders which have been mixed uniformly using wet milling by a planetary mill and then pressed at 250 MPa pressure. Time of milling and time of sintering are of investigated parameters in this paper. In order to achieve sintering، prepared samples were heated at the temperatures of 1550°C for 60 and 90 minutes in a microwave oven. Density، porosity، three-point bending strength، hardness، microstructure and phase analysis of prepared samples were measured and compared with those samples sintered in conventional furnace. Results showed that using microwave sintering can economize time and cost; it can also yield to a high density، more tetragonal zirconia formation and extraordinary strength of alumina-mullite-zirconia composites.