Characterization of alumina matrix nanocomposite with ZrO2 inclusions densified by spark plasma sintering

Alumina matrix composites with nanometric inclusions of 5 vol% ZrO2 were prepared and consolidated by the spark plasma sintering method. Nearly fully dense composites could be obtained by sintering at 1300 °C for 2 min. Under these conditions, no grain growth of the alumina particles could be discerned. The effect of temperature and hold time on density and microstructure were also investigated. Microhardness measurements showed that the inclusion of nanometric zirconia increased the hardness by about 10%, to 22 GPa.