添加剂对Al_2O_3/BN可加工陶瓷性能的影响  

Effect of Additions on the Properties of Al_2O_3/BN Machinable Ceramics

作　　者：李永利[1] 乔冠军[1] 金志浩[1] 

机构地区：[1]西安交通大学,陕西西安710049

出　　处：《稀有金属材料与工程》2004年第7期744-747,共4页Rare Metal Materials and Engineering

基　　金：国家自然科学基金资助(50072017)

摘　　要：采用Si3N4和SiC作为Al2O3/BN可加工陶瓷的添加剂,考察了添加剂种类和含量对材料力学性能及可加工性能的影响。研究表明,2种添加剂均对调节体系中由于热膨胀失配所引起的大的内应力起到积极的作用。材料的抗弯曲强度随添加剂含量的增加而提高,同时可加工性能略有降低。尤其是Si3N4的加入使体系在热压烧结过程中原位反应生成液相x-Sialon,显著降低了烧结温度,促进材料的致密化。The effect of additions of Si3N4 and SiC on the mechanical properties of Al2O3/BN machinable ceramics was investigated. The experimental results indicate that both additives contribute to densification and, help to relax the thermal expansion mismatch between Al2O3 and BN, thereby improving the mechanical properties. The bending strength of Al2O3/BN increases with increase of additive content, while the machinability is only slightly degraded. Remarkably, the Al2O3/BN nanocomposite powder with added Si3N4 could be hot-pressed in nitrogen at 1700degreesC, with almost no porosity, 100degreesC lower than that with additive SiC. Si3N4 accelerated the sintering of the nanocomposite powder because of the appearance of liquid x-Sialon during hot-pressing.

关 键 词：氧化铝 氮化硼 陶瓷 添加剂 力学性能 可加工性 

分 类 号：TQ174[化学工程—陶瓷工业]