Properties of alumina 10 vol% zirconia composites — The role of alumina starting powders

Due to their high strength, hardness and abrasion resistance alumina zirconia composites (ZTA) are well established materials for mechanical engineering and biomedical applications. While the basic material concept is simple, the effects of changes in raw materials are insufficiently investigated. In this study five different submicron alumina powders are combined with 10 vol% of an unstabilized zirconia powder. Samples are consolidated by hot pressing at 1475–1600°C and investigated with respect to microstructure, mechanical properties and phase composition. Adaptation of sintering parameter allows to manufacture ZTA of acceptable quality from all starting powders. Alumina powders of higher purity help to retain a well dispersed and stable microstructure at higher sintering temperatures while in ZTA from alumina powders of lower purity segregation and grain growth is observed at high sintering temperature.