水溶性共聚物为交联剂的凝胶注成型AlN陶瓷的研究

本研究采用一种快速凝胶的氮化铝凝胶通过在氮气气氛下烧结制备AlN陶瓷。将AlN粉体、少量的Y₂O₃粉体(烧结助剂)和去离子水以一定比例混合制得AlN浆料, 在浆料中加入一种新型的水溶性共聚物Isobam(由异丁烯和马来酸酐形成的共聚物)作为交联剂, 所得浆料在室温空气中自发凝胶成型。研究了Isobam和AlN、Y₂O₃粉体表面的有机包裹剂聚亚氨酯对浆料流变性能和凝胶性能的影响。结果表明, 加入0.3wt% Isobam可制备出固含量达52vol%的低粘度(0.2 Pa·s)AlN浆料。将凝胶干燥并脱粘, 获得的AlN素坯在氮气气氛下1800 ℃烧结4 h, 可制备出鳍状AlN陶瓷, 所得陶瓷的密度为3.33 g/cm³, 热导率为204 W/(m·K)。

Gelcasting of Aluminum Nitride Using a Water-soluble Copolymer

AlN ceramic was fabricated via a rapid gelation of AlN slurry and sintering in nitrogen at 1800 ℃ for 4 h. The AlN slurry was made of AlN powder, small amount of Y₂O₃ powder (sintering aid), deionized water. A new water-soluble copolymer of isobutylene and maleic anhydride (commercial name Isobam) was added into the slurry, and the resultant slurry gelled spontaneously in air at room temperature. The effects of Isobam and polyurethane on rheological properties and gelling behavior were evaluated. Results showed that concentrated AlN slurry (52vol%) with low viscosity (0.2 Pa·s) was obtained with an addition of 0.3wt% Isobam. The final AlN ceramic had a fin-like shape, a density of 3.33 g/cm³ and a thermal conductivity of 204 W/(m·K).