Si_3N_4原料对形成长颗粒Ca-α-Sialon晶粒形貌的影响  

Effect of Si_3N_4 Starting Powders on Formation of Elongated Ca-α-Sialon Grains

作　　者：李雅文[1] 王佩玲[1] 严东生[1] 程一兵[2] 

机构地区：[1]中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室,上海200050 [2]澳大利亚Monash大学材料工程系

出　　处：《无机材料学报》2000年第1期62-66,共5页Journal of Inorganic Materials

基　　金：国家自然科学基金!59810761327和59872049

摘　　要：针对固定组份的Ｃａ－α－Ｓｉａｌｏｎ系统Ｃａ１.８Ｓｉ６.６Ａl５．４Ｏ１．８Ｎ1４．２），选用不同α／β比值的Ｓｉ３Ｎ４原料考察了无压烧结所得材料的致密化、反应过程及显微结构的异同．结果表明，由两种不同α／β比值的Ｓｉ３Ｎ４原料制备的材料,其α－Ｓｉａｌｏｎ晶粒均具有长颗粒的形貌．但高β相含量的Ｓｉ３Ｎ４原料会阻碍Ｃａ－α－Ｓｉａｌｏｎ材料的致密化，β－Ｓｉ３Ｎ４相完全消失的温度也比α－Ｓｉ３Ｎ４提高了１００℃．原料中β相含量废越高，提供给α－Ｓｉａｌｏｎ生长的核心数越少，α－Ｓｉａｌｏｎ晶粒越粗大，而且高β相Ｓｉ３Ｎ４原料中宽的粒径分布导致所得α－Ｓｉａｌｏｎ晶粒尺寸的不均匀．Two kinds of Si3N4 starting powders with different a/B ratios were used to prepare Ca-α-Sialon with the composition Ca1.8Si6.6A15.4O1.8N14.2 by pressureless sintering. The densificationprocess, reaction sequence and microstructure of the corresponding materials were studied by XRDanalysis and SEM observation. Elongated a-Sialon grains were observed in the materials sinteredwith either St3N4 starting powders. On the other hand, Si_3N_4 starting powders with high Bphase content resulted in poorer densification during sintering and the temperature for completedissolution of P-Si_3N_4 was 100℃ higher than that for α-Si_3N_4. The higher the content of B phasein the starting powders, the fewer nucleation sites there were, and the coarser a-Sialon grains were.A broad size distribution of the St3N4 starting powders led to the inhomogeneity of a-Sialon grainsizes.

关 键 词：长颗粒 显微结构 氮化硅 SIALON陶瓷 晶粒形貌 

分 类 号：TQ174.758[化学工程—陶瓷工业] TQ174.1[化学工程—硅酸盐工业]