碳热还原氮化法合成O′-Sialon粉  

Synthesis of O′-Sialon powder by carbothermal reduction-nitridation

作　　者：杨建[1] 薛向欣[1] 刘欣[1] 姜涛[1] 王文忠[1] 

机构地区：[1]东北大学材料与冶金学院,沈阳110004

出　　处：《中国有色金属学报》2002年第2期347-352,共6页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目 (5 98740 12 ) ;教育部高等学校骨干教师计划基金资助项目 (教技司 [2 0 0 0 65 ] ) ;辽宁省科学技术基金资助项目 (0 0 2 0 0 9)

摘　　要：以纳米SiO2 ,Al(OH) 3 和碳黑为原料 ,在 14 0 0℃N2 气氛下采用碳热还原氮化法合成出O′ Sialon粉。绘出了 14 0 0℃时体系的优势区域图 ,用XRD分析法测定了产物相组成及相对含量 ,用TEM观察了产物的形貌 ,并用EDX分析法测定了产物中O′ Sialon的Si和Al摩尔比。在此基础上 ,研究了保温时间和添加剂含量对合成过程的影响 ,对合成过程机理进行了探讨。结果表明 :保温 7h ,含 3%添加剂的试样中O′ Sialon含量最高 ,达70 %左右 ,O′ Sialon中z值基本达到 0 .3。添加剂含量的增加有利于Al2 O3 向O′ Sialon中固溶。SiO是碳热还原氮化过程的中间产物 ,SiO的挥发导致体系较大的质量损失和Al2 O3 的残存。保温时间超过 8h ,体系气氛的改变使O′ Sialon分解转化为 β′O′ Sialon powder was synthesized by means of carbothermal reduction nitridation with nano SiO 2, Al(OH) 3 and carbon black as raw materials at 1?400?℃ in N 2 atmosphere. Thermodynamic predomination region diagram for the Si 3N 4/Si 2N 2O/SiC/SiO 2 system at 1?400?℃ was presented. Phase composition of reaction products was determined by XRD. Morphology of the synthesized O′ Sialon was observed by TEM and molar ratio of Si to Al was determined by EDX. Effects of holding time and addtive content on synthesis process was studied and synthesis mechanism was discussed in detail. It shows that when the holding time is 7?h and additive content is 3%, the content of O′ Sialon in the sample reaches the highest value of 70% or so and the value of z , solid solubility of Al 2O 3 in O′ Sialon, is near 0.3. The increase of additive content is favorable for the solid state solution of Al 2O 3 into O′ Sialon. SiO is an intermediate product for the process of carbothermal reduction nitridation. Volatilization of SiO results in great mass loss of the samples and the remaining of Al 2O 3 in reaction products. If the holding time is above 8h, O′ Sialon will be converted into β′ Sialon because of the change of atmosphere in the system.

关 键 词：O′-Sialon粉 碳热还原氮化 合成机理 工程陶瓷 

分 类 号：TQ174.75[化学工程—陶瓷工业]