(1. 中南大學(xué) 冶金科學(xué)與工程學(xué)院，長沙 410083；
2. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 研究凝膠注模坯體的液體干燥，通過質(zhì)量稱量和尺寸測量等手段分析液體干燥劑類型與濃度和坯體固相體積分?jǐn)?shù)與尺寸對坯體質(zhì)量損失率和收縮率的影響規(guī)律。結(jié)果表明：在液體干燥過程中，水分在濃度梯度產(chǎn)生擴(kuò)散的機(jī)制和表面張力差產(chǎn)生的置換機(jī)制的作用下被排出，同時，在高分子網(wǎng)絡(luò)協(xié)同擴(kuò)散機(jī)制作用下，坯體發(fā)生收縮。酮類液體干燥劑的干燥能力優(yōu)于醇類的，并且在同種類液體干燥劑中，低分子量干燥劑的干燥能力優(yōu)于高分子量干燥劑的。較合適的液體干燥劑為丙酮和乙醇。液體干燥劑濃度越高，坯體的質(zhì)量損失率越大，但收縮率越小，因此液體干燥的劑濃度不能過高。坯體的固相體積分?jǐn)?shù)越低、高徑比越大，干燥效果越好。
關(guān)鍵字: 坯體；液體干燥；凝膠注模；液體干燥劑
（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
