Liquid drying of BeO gelcast green bodies using ethanol as liquid desiccant
(School of Materials Science and Engineering, Central South University, Changsha 410083, China)
Abstract: BeO gelcast green bodies were dried by liquid drying method with liquid desiccant ethanol. Effects of ethanol concentration, solids loading and aspect ratio of green body on the moisture and shrinkage of green bodies were studied through measuring mass and dimension. Additionally, liquid drying stress was analyzed and a model of the initial stage drying stress was established. The results show that higher ethanol concentration, lower solids loading and higher aspect ratio of gelcast green bodies increase the drying rate. Increasing the ethanol concentration decreases the shrinkage rate. Liquid drying stress is generated due to a non-uniform drying rate. During the process of liquid drying, the inner drying stress of the green body changes from compressive stress to tensile stress, while the outer drying stress changes from tensile stress to compressive stress.
Key words: BeO; gelcasting; green body; liquid desiccant; ethanol; drying rate; shrinkage rate; drying stress