(1. 中南大学 冶金科学与工程学院，长沙 410083；
2. 中南大学 材料科学与工程学院，长沙 410083)
摘 要: 研究凝胶注模坯体的液体干燥，通过质量称量和尺寸测量等手段分析液体干燥剂类型与浓度和坯体固相体积分数与尺寸对坯体质量损失率和收缩率的影响规律。结果表明：在液体干燥过程中，水分在浓度梯度产生扩散的机制和表面张力差产生的置换机制的作用下被排出，同时，在高分子网络协同扩散机制作用下，坯体发生收缩。酮类液体干燥剂的干燥能力优于醇类的，并且在同种类液体干燥剂中，低分子量干燥剂的干燥能力优于高分子量干燥剂的。较合适的液体干燥剂为丙酮和乙醇。液体干燥剂浓度越高，坯体的质量损失率越大，但收缩率越小，因此液体干燥的剂浓度不能过高。坯体的固相体积分数越低、高径比越大，干燥效果越好。
关键字: 坯体；液体干燥；凝胶注模；液体干燥剂
（1. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:Gelcasting green bodies were dried by solvent drying method, and the influences of type and concentration of liquid desiccant, solids loading and size of green body on the mass loss fractions and shrinkage fractions of green bodies were analyzed through measuring the mass and dimension. The results show that water is discharged due to the diffusion mechanism derived from moisture concentration differences on either side of the green body and the replacement mechanism developed from the gradient of osmotic pressure between the two media. The drying capability of ketones solvent is better than that of the alcohol solvent, and the drying capability of the same kind of solvent with low molecular mass is larger than that of the solvent with high molecular. Acetone and ethanol are suitable liquid desiccant. The more concentration of liquid desiccant is, and the more mass loss fraction is, but less shrinkage fraction of the green body is. The drying efficiency of the green body with lower solids loading and higher aspect ratio is better.
Key words: green body; solvent drying; gelcasting; liquid desiccant
