Microstructure Analysis of the ZrO2/Al2O3 Multi-phase Ceramics

Scanning electron microscopy (SEM) with X-ray mapping analysis was applied to systematically study the microstructure of ZrO2/Al2O3 multi-phase (ZTA) ceramics prepared by firstly cold isostatic pressing of the as-prepared powders with different formulas and then normal pressure sintering of green bodies at different temperatures, which was proposed to illustrate the toughening mechanism of ZrO2 phase as well as the effect of the microstructure on the fracture toughness of the ZTA ceramics. In addition, XRD analysis was carried out to characterize the phase composition and validate the mapping data from microanalysis. Results obtained in this study demonstrate that the amount of sintering aids added to decrease the sintering temperatures as well as the distribution of ZrO2 particles in Al2O3 particles both play key roles in the microstructure and fracture toughness of ZTA ceramics, which indicates that microanalysis have important directive to the preparation of multi-phase ceramics with high performance.