热处理过程中纳米非晶Si－N－C粉的晶化及微结构变化研究  

Study of Crystallization and Microstructure Evolution of Nano Amorphous Si-N-C Powders During Heat Treatment

作　　者：李亚利[1] 梁勇[1] 郑丰[1] 肖克沈[1] 胡壮麒[1] 

机构地区：[1]中国科学院金属研究所快速凝固非平衡合金国家实验室,中国科学院金属研究所微晶与激光加工实验室

出　　处：《无机材料学报》1996年第1期162-166,共5页Journal of Inorganic Materials

摘　　要：本文在１４７３～１９７２Ｋ温度范围内对激光合成的、平均粒径为３０ｎｍ的非晶Ｓｉ－Ｎ－Ｃ粉进行热处理（ｌａｔｍ．Ｎ２，１ｈ）；研究了粉体的晶化及微结构变化，结果表明，纳米非晶Ｓｉ－Ｎ－Ｃ粉具有短程有序的亚稳结构，此亚稳结构在＞１５２３Ｋ发生稳定团相分离，在１７７３Ｋ开始形成α－Ｓｉ３Ｎ４；β－ＳｉＣ，此时粒子间出现明显的表面扩散形成粒子簇；到１８７３Ｋ晶化加剧，α－Ｓｉ３Ｎ４和β－ＳｉＣ明显增多，并有少量的石墨碳形成。在１７７３～１８７３Ｋ，由固相分离形成α－Ｓｉ３Ｎ４／β－ＳｉＣ纳米复合结构。The laser-synthesized St-N-C powders with mean particle diameter of 30urn were annealed between 1473～1973K. The crystallization and microstructure evolution of the powders were studied. There existed a metalstable structure with a short ordered range in the nano amorphous St-N-C powders. The metastable structure began solid phase separation at a temperature more than 1523K. Higher than 1773K,the phaseseparation resulted in the formation of or-St3N4 and β-SiC, and the surface diffusion among Si-N-C particles led to the formation of particlate cluster. At 1873K, the amount of or-St3N4 and β-SiC increased rapidly, accompanied by the appearence of a small amount of fiber-like graphite. Between 1773～1873K, α-Si3N4/βSiC nano composite structure was formed from the solid phase separation.

关 键 词：热处理 晶化 纳米粉 氮化硅 复合陶瓷 碳化硅 

分 类 号：TQ174.758[化学工程—陶瓷工业]