AlN陶瓷低温烧结过程中氧化控制与性能研究

Oxidation Control and Properties Study of AlN Ceramics Sintered at Low-Temperature

采用纳米级的AlN粉并以Y2O3-CaF2作烧结助剂于1600℃下制备AlN陶瓷,对AlN陶瓷物相组成、相对密度、微观结构和热性能进行了表征,针对AlN陶瓷烧结过程中易氧化的问题,分析了氮化铝陶瓷在烧结过程中氧化的机理,提出了防止AlN陶瓷制备过程中氧化的措施。研究表明:将AlN坯体置于含有一定量碳粉的AlN埋粉中于N2气氛下烧结,生成还原性气体CO,有效避免了AlN烧结过程中的氧化问题。其中添加3wt%Y2O3-2wt%CaF2作烧结助剂,1600℃常压条件下制备了高热导率的致密AlN陶瓷。

A1N ceramics doped with Y2O3--CaF2 were sintered at 1600℃with using nano--sized A1N powders. The density, thermal properties, and A1N phase change and microstructure of sintered A1N ceramics were tested and analyzed. For A1N ceramic＇s easy oxidation problems during sintering process, we analysis aluminum nitride ceramics mechanism of oxidation, and the measures is proposed to prevent the oxidation during the preparation of A1N ceramics. The results show that the A1N ceramic＇s oxidation problem can be avoided by A1N body buried in a certain amount of A1N and carbon with N2atmosphere. Especially high thermal conductivity and dense A1N ceramics doped with 3wt %Y2O3- 2wt%CaF2and sintered at 1600℃are prepared by pressureless sintering at a lower temperature.