中文摘要：

针对凝胶注模陶瓷素坯在加热干燥过程中收缩较大的问题,采用固体干燥剂干燥工艺以提高陶瓷素坯的干燥尺寸精度。重点研究了CaO、无水MgSO4和SiC粉体3种固体干燥剂的成分、粒径尺寸以及环境湿度对陶瓷素坯干燥线收缩率的影响规律,分析了具备不同物理化学属性的3种固体干燥剂对素坯失水速率和表面蒸汽压的影响规律,并结合红外光谱测试了凝胶结构均匀性对素坯干燥尺寸精度的影响规律,采用CT扫描对陶瓷素坯的尺寸变化进行了表征。结果表明：在相同的温度和湿度条件下,固体干燥剂干燥工艺降低了陶瓷素坯干燥前期的失水速率,延长了等速干燥阶段的时间,并提高了凝胶结构均匀性和素坯强度,因此降低了素坯干燥线收缩率;当温度为40℃时,采用2μm粒径的CaO干燥剂可将陶瓷素坯的干燥线收缩率降至0.12%。

英文摘要：

A drying process with solid desiccant is carried out to restrain large shrinkage and to improve the dimensional accuracy of ceramic green body during heating drying. The effects of particle size and humidity of three kinds of solid desiccants including CaO, anhydrous MgSO4 and SiC on shrinkage are investigated. The improvement of drying shrinkage of ceramic green body is analyzed in terms of dehydration rate, surface vapor pressure and homogeneity of gel structure. The dimensional variation of the ceramic body is characterized by computed tomography （CT）. The results show that drying process with solid desiccant can reduce the dehydration rate at initial stage, extend the constant drying period and improve the homogeneity of gel structure and the strength of ceramic body, thus the dimensional accuracy of the ceramic body is greatly heightened, and the drying shrinkage of the ceramic body lowers to 0.12% by means of CaO powder （particle size 2 μm） at 40 ℃.