【摘要】 本文研究了纳米级ＺｒＯ２粉末的悬浮流变特性与注浆成型，结果表明纳米粉末具有不同于亚微米粉末的特性：纳米粉末悬浮性良好，但料浆呈触变性；具有低的最高含固量（对应于粘度５×１０－２Ｐａ·ｓ）５５ｗｔ％，低的生坯密度３６．４％，高的烧结收缩率３４％和较高烧结温度１６００℃．纳米粉末表面吸附大量紧吸附水使自由流动水份减小造成浆料含固量低，而紧吸附水不能被石膏模毛细管力排除又产生低生坯密度并导致高烧结收缩率．更多还原

【Abstract】 The suspension, rheology and slip casting of nanometer powder of Y-TZP in aqueous media were studied. The powder was well suspended when the poly (acrylic acid), sodium pyrophosphate and both of them were used as a dispersant. The slurry exhibited some characteristics, in comparison with submicrometer Y-TZP powder, of (A) thixotropic behaviour, (B) low solid content of 55wt% at the viscosity of 5×10-2Pa.s, (C) low relative density, less than 36.4%, of green body, and (D) large shrinkage, 34%, of the formed cakes sintered at 1530～1600℃ for 4h. All of the properties were attributed to the nanometer powder with large specific surface absorbing a large amount of water. This sort of water leaded to decreasing free fluid-water between the particles and thereafter resulted in high viscosity or low solid content of the slurry. Also, the tightly absorbed water can not be taken in by the plaster of paris mold owing to the capillary force in the mold less than that in the formed green bodies, which caused the low relative density. SEM obserwtions showed the average grain size of Y-TZP was 1.6μm at the fired body with 98.5% theoretical density, sintered at 1600℃ for 4h.更多还原