Effects of sintering curves on microstructure, physical and mechanical properties and on low temperature degradation of zirconia-toughened alumina

The objective of this work was to study two-step sintering as a means of controlling the microstructure of coarse Al 2 O 3 matrix composites containing submicrometric and nanometric inclusions of ZrO 2 ranging from 0–30 wt. % by weight based on commercially available powders and evaluate its hydrothermal degradation as function of a water vapour pressure and its mechanical properties. The results showed that two-step sintering allowed a more efficient microstructural control than single-step sintering, resulting in good mechanical properties. The highest flexural strength was achieved for ZTA samples sintered in two-stage sintering conditions TSS2 with T1 = 1560 °C for 3 h, T2 = 1460 °C for 8 h. The studied composites showed good resistance to hydrothermal degradation compared to composites sintered in single step sintering conditions.