AlN陶瓷的凝胶注模成型及其导热性能

为了解决AlN陶瓷难于制备复杂形状、生产成本高、重复性差等问题,采用无毒的壳聚糖体系,以Y2O3+CaF2为烧结助剂,利用凝胶注模成型及无压烧结制备了AlN陶瓷.利用粘度计、X射线衍射仪、扫描电镜等对AlN陶瓷浆料性能和AlN陶瓷的显微组织与导热性能进行研究.结果表明:戊二醛浓度、pH值及壳聚糖含量对凝胶化时间有影响;醋酸含量降低、固相含量增加会使AlN陶瓷浆料粘度下降;真空处理有助于陶瓷浆料中气泡的去除;Y2O3+CaF2烧结助剂不但可以降低烧结温度,还可有效改善AlN陶瓷的导热性能;固相含量为52vol.%的AlN陶瓷坯体无压烧结后,热导率达到95.6 W/(m·K).

Thermal Properties of AlN Ceramics Prepared by the Gelcasting Method

Abstract：In order to solve problems of preparing products with completed shape, high cost of production and poor repeatability of AlN ceramics, gelcasting and pressureless sintering method were used to prepare A1N ceramics with nontoxic chitosan system and with Y2O3 ＋ CaF2 as sintering additive. The viscometer, X-ray diffraction and scanning electron microscopy were used to investigate the properties of A1N ceramic slurry and the microstructures and thermal properties of A1N ceramics. The results show that glutaraldehyde concentration, pH value and chitosan content have and influence on the gelation time. Vacuum processing is benefitial to removing air bubbles. Y2O3 ＋ CaF2 sintering additive not only reduces the sintering temperature, but also effectively improves the thermal conduc- tivity of A1N ceramics. Thermal conductivity of the pressureless sintering A1N ceramics with 52vol. % solid content can reach 95.6 W/（m · K）.