氮化硅(Si_3N_4)微粉的超高压烧结研究  

A STUDY ON SINTERING BEHAVIOR OF SILICON NITRIDE Si_3N_4 MICRO POWDER UNDER HIGH PRESSURES

作　　者：沈中毅[1] 孙继荣[1] 刘世超[1] 刘勇[1] 黄振坤[2] 

机构地区：[1]中国科学院物理研究所,北京100080 [2]中国科学院上海硅酸盐研究所,200050

出　　处：《高压物理学报》1991年第4期267-274,共8页Chinese Journal of High Pressure Physics

基　　金：中国科学院高性能陶瓷与超微结构开放实验室资助项目

摘　　要：氮化硅(Si_3N_4)是具有优良性能的陶瓷材料,具有广泛的工程应用前景。但由于这种化合物属于共价结合性质并具有很高的熔点,陶瓷的烧结需要在很高的温度下进行。本文探讨了在超高压力下这种材料的烧结行为的变化。对含有AlN,Al_2O_3及少量La_2O_3添加物的Si_3N_4微粉在3～7GPa,800～2000℃的压力温度范围内进行烧结,并应用X线衍射,扫描电子显微镜观察及密度测量等方法研究了烧结样品。结果表明高压力可以大大促进Si_3N_4的α→β转变及固相反应,降低烧结温度。高压下烧结过程分为两个阶段:低温下以粉末粒子结合为主要内容的过程及高温下各物相间的相变和固相反应为主的过程。研究表明,超高压力下烧结没有改变所研究组份样品的复合相组成。Silicon nitride (Si3N4) is a series of ceramic material with outstanding technological properties and has been widely investigated for various engeering applications. On the other hand , these kind of ceramics are of covalent bounding and are very difficult to sinter. This investigation was conducted for understanding the high pressure sintering behavior of Si3N4 micro-powder samples. Sintering was performed at high pressures ranging from 3 to 7GPa and temperatures in a range of 800 2000℃. The sintered samples arc composed of Si3N4 and AIN,Al2O3 and La2O3 additives. The sintering compacts were characterized with the aid of X-ray diffraction, scanning electron microscopy and density measurement methods. The obtained results shows that the α→β convcrssion of Si3N4 phase is greatly promoted by highly compression and the powder samples could be sintered at quite lower temperatures. Additionally . the high pressure sintering process is observed to be consist of two stages; at moderate temperatures the sintering process con sists of only the joinning of the composited particles, while at high enough temperatures, the solid state reactions between the composite powders can be greatly proceeded and resulted in a fully sin tercd compacts.

关 键 词：氮化硅 烧结 陶瓷 高压力效应 

分 类 号：TQ174.758[化学工程—陶瓷工业]