Microwave sintering of alumina–zirconia nanocomposites

This work involved an investigation of microwave hybrid fast firing of alumina–zirconia nanocomposites aimed at suppressing grain growth, using commercial alumina powder and yttria-stabilized zirconia powder. The nanocomposites studied here contained 1, 3 and 5 vol.% of zirconia. The powders were ball-mixed and compacted under cold isostatic pressure at 200 MPa. The samples were microwave hybrid fast sintered in a multimode microwave furnace at 2.45 GHz using susceptor material, which acted as a hybrid heating element. The densities of the sintered samples were determined by the Archimedes method. The sintered samples reached densities of 99% in sintering cycles of 30 and 35 min, with uniform microstructures and without significant grain growth, showing powder particle size to average grain size ratios exceeding 1:2.