超臨界非水溶媒を用いるセラミックス粉末の合成

抄録

The survey deals with the preparation of ceramic powders by crystallizing in nonaqueous solvents and supercritical drying. The sintering behaviors and mechanical properties of sintered bodies are very much sensitive to the crystallizing conditions, since hard agglomerates formed when the precipitated gels were crystallized by normal calcination in air, whereas soft agglomerates formed when they were crystallized in water or organic solvents. CeO₂-ZrO₂ powders crystallized in methanol and water at 250°C were sintered to full theoretical density at 1100° and 1400°C, respectively, whereas that crystallized by calcination in air at 450°C was sintered to only 95.2% of theoretical density, even at 1500°C. Sintered bodies fabricated using the powders crystallized and dried using supercritical methanol possessed excellent mechanical properties.