钟亮
,
陈晓红
,
宋怀河
,
胡子君
,
孙陈诚
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2014.01.014
以硝酸氧锆为锆源,尿素为凝胶促进剂,通过水热凝胶法结合超临界乙醇干燥,可成功制备出具有良好纳米三维网络结构的ZrO2气凝胶.采用透射电镜(TEM)、比表面积及孔隙度分析仪(BET),X射线衍射仪等测试手段对其结构进行了表征与测试.结果表明,ZrO2气凝胶主要由无定型和四方晶相组成,其比表面积为445 m2/g,孔径主要分布在5～7 nm和30～40 nm两处.
关键词:
ZrO2
,
气凝胶
,
超临界干燥
,
比表面积
Liping LIANG
,
Shue DANG
,
Dong WU
,
Yuhan SUN
材料科学技术（英文）
Coprecipitation supercritical fluid drying technology has been employed to synthesize calcia-stabilized zirconia ultrafine powder with low-cost inorganic salts as the starting materials. The sintering behaviors of these powders were also investigated. The results showed that supercritical fluid drying could effectively alleviate the hard agglomeration of grains during the gel drying process, and the morphology of the powder retained the network texture of the original gel. The resulting particles were characterized by small particle size (5~20 nm), better monodispersity and high surface area, which gave rise to high activity and sinterability. Consequently, these powders could readily be compacted into the desired shape and their densification could be carried out in shorter time and at lower temperatures. For instance, nanometer-sized powder calcined at 600ºC for 2 h could be cold-pressed into a green body and sintered at 1100º for 0.5 h to attain a dense body with bulk density of 5.9718 g/cm3 and specific pore volume of 0.0008 cm3/g.
关键词:
Calcia-stabilized zircornia
,
null
,
null
,
null
