不同制备工艺对多孔氮化硅陶瓷微观结构的影响  

The Influence of Different Fabricating Processing on the Microstructure of Porous Si_3N_4

作　　者：张晓霞[1] 山玉波[1] 张伟儒[2] 李伶[2] 侯竟伟[3] 张训虎[2] 

机构地区：[1]东北大学机械工程与自动化学院,辽宁沈阳110004 [2]山东工业陶瓷研究设计院,山东淄博255031 [3]沈阳建筑大学交通与机械工程学院,辽宁沈阳100168

出　　处：《沈阳建筑大学学报（自然科学版）》2006年第6期1038-1042,共5页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家863计划项目(2002AA305510);国家自然科学基金(50475167);辽宁省教育科学基金(05L356)

摘　　要：目的制备高气孔率、高强度的氮化硅陶瓷,分析复合助剂A、Al2O3、碳粉、烧结温度等因素对高气孔率、高强度的氮化硅陶瓷材料微观结构的影响.方法采用部分烧结工艺和添加造孔剂工艺制备实验材料.利用阿基米德法、三点弯曲法测试了材料的密度、显气孔率及弯曲强度;借助扫描电子显微镜(SEM)进行微观结构分析.结果成功制备出结构比较均匀并且有高气孔率和较高强度的氮化硅陶瓷,当气孔率高达51.14%时,强度仍具有172 MPa.结论均匀气孔获得主要是由长柱状β-Si3N4晶粒在三维空间搭接构成的,烧结温度提高有助于长柱状β-Si3N4的转变与发育;柱状晶强度高、缺陷少是获得高强度的主要原因.在一定范围内,碳粉含量增加有助于气孔率的提高.The purpose of this paper is to fabricate silicon nitride ceramics with high porosities and high strength, so as to analyze the influence of the sintering additives A, Al2O3, carbon powder and sintering temperature on the microstructure of silicon nitride ceramics. Partial sintering and the adding of carbon inclusions are used to make the experimental material. The volume density, open porosities and flexure strength of porous silicon nitride ceramics are measured respectively by Archimedes and three- point bending methods. Microstructure is analyzed by means of scanning electron microscopy （SEM）. Silicon nitride ceramics with even structure, high porosities and high strength have been successfully made, and the sintered porous Si3N4 ceramics have the strength of 172 MPa when the porosities are 51.14 %. The even pores are formed by the banding- up of pillar β- Si3N4. The enhancement of sintering temperature is liable to the transformation and growth of pillar β- Si3N4 ; the high strength of pillar structure and low defect are the main reasons for good mechanical performances. More carbon powder is helpful in enhancing the porosities in a sense.

关 键 词：氮化硅 微观结构 气孔率 弯曲强度 

分 类 号：TB321[一般工业技术—材料科学与工程]