Preparation of Zirconia-toughened Alumina Ceramics through the Dispersal Basic Carbonate Precursors

摘要

Using NH_4HCO_3 solution as precipitant, the ultrafine 3Y-ZrO_2/Al_2O_3 precursors were prepared by the liquid-phase precipitation method. The well-dispersible ZrO_2/Al_2O_3 composite nanopowders with particle size 10nm were obtained by calcining the precursor at 1000℃. The XRD patterns show no γ-Al_2O_3 and θ-Al_2O_3 formed during calcination. The powders have excellent sinterability and the relative density of specimen is up to 99% after sintering the green compacts at 1550℃. Microstructural analysis of the sintered bodies reveals the uniform distribution of the zirconia grains in the alumina matrix.