Effect of isothermal sintering time on the properties of the ceramic composite ZrO{sub}2-Al{sub}2O{sub}3

摘要

In this work the influence of isothermal sintering time on the microstructural development of ZrO{sub}2-Al{sub}2O{sub}3 composite was studied. Powder mixture of ZrO{sub}2 containing 20 wt% Al{sub}2O{sub}3 was prepared by milling, compaction and sintering at 1600°C, in air. The isothermal sintering time at 1600°C was varied between 0 and 1440 min. The sintered samples were characterized in terms of phase composition and relative density. Their microstructures were characterized by grain size distributions and average grain size. These results were evaluated using the classic grain growth equation as a function of time, determining the grain growth exponent of these materials. Furthermore, the microstructural aspects were related to the mechanical properties (Vicker's hardness and fracture toughness) of these composites.