Physical and mechanical properties of Ta2O5 doped zirconia-toughened alumina (ZTA) composites

The aim of this research is to investigate the characteristics and mechanical properties of Ta2O5 doped zirconia-toughened-alumina composites. Samples of partially stabilized-zirconia toughened alumina (ZTA) with 5% volumetric ZrO2 addition doped with Ta2O5 in amounts ranging between 0.12 and 0.36 vol% were prepared by sol–gel technique. The powders of each composition were uniaxially pressed into discs and rectangular bars, and then sintered at 1500 °C up to 1650 °C for 1 h in air. The phase constitution and microstructures of sintered ceramic composites were characterized using X-ray diffractometer and scanning electron microscope respectively. The mechanical properties of the ceramic composites were evaluated by the Vickers hardness, flexural strength and fracture toughness tests. It was found that increase in Ta2O5 concentration has a strong effect on the densification behavior and mechanical properties of the ZTA composites.