【摘要】 本文研究了平均粒径为２０ｎｍ的ＺｒＯ＿２粉末塑性挤制成型．结果表明。在粘合剂ＰＶＡ含量为２～６ｗｔ％范围内，可塑性指标１．０～４．０与可塑性粘土相当，但也具有高含水率４０～６０ｗｔ％；泥团的应力－应变曲线呈类超塑性，具有低的生坯密度（＜２７％ｔｈ）和高的烧成收缩率（４７％）；１６５０℃×４ｈ烧结相对密度为９９．５％，晶粒尺寸３～１０μｍ．纳米粉末的小粒径导致泥团的高表面张力，使之具有高可塑性，而纳米粒子表面吸附大量水份（＞８０ｖｏｌ％）构成可滑动界面是产生类超塑性和低生坯密度的原因更多还原

【Abstract】 Plastic extrusion forming was studied for tetragonal zirconia powders with 20nm in diameter containing polyacryl alcohol (PVA) binder. Plastic bodies had plasticity index 1.0-4.0, comparable with clay, and water content 40-60wt%, when 2-6wt% PVA was used. The bodies also exhibited superplasticity at low stress level in stress-strain curves. Green articles had a low relative density (<27%) and underwent a large linear shrinkage (47%) on sintering of 1650℃ for 4h. The green size of samples sintered at 1650℃ 4h was 3-10μm and density of 99.5% theoretical. The observed high plasticity is attributed to the small particle size of the powders leading to a great force. The superplasticity and low green density are resulted from the large specific surface of the powder absorbing a great amount of water (>80vol%) between the pericles.更多还原