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.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
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
