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无机材料学报

无机材料学报

• 研究论文 • 上一篇    下一篇

Si3N4原料对形成长颗粒Ca-α-Sialon晶粒形貌的影响

李雅文1; 王佩玲1; 严东生1; 程一兵2   

  1. 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
  • 收稿日期:1999-01-11 修回日期:1999-03-15 出版日期:2000-02-20 网络出版日期:2000-02-20

Effect of Si3N4 Starting Powders on Formation of Elongated Ca-α-Sialon Grains

LI Ya-We1; WANG Pei-Ling1; YAN Dong-Sheng1; CHENG Yi-Bing2   

  1. 1. State Key Lab of High Performance Ceramics and Superfine Microstructure; Shanghai institute ofCeramics; Chinese Academy of Sciences; Shanghai 200050; China; 2. Department of Materials Engineering; Monash University, Clayton, Victoria, 3168, Australia
  • Received:1999-01-11 Revised:1999-03-15 Published:2000-02-20 Online:2000-02-20

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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．

关键词: Ca, 长颗粒α-Sialon, 反应过程, 显微结构

Abstract: Two kinds of Si3N4 starting powders with different α/β ratios were used to prepare
Ca-α-Sialon with the composition Ca1.8Si6.6Al5.4O1.8N14.2 by pressureless sintering. The densification process, reaction
sequence and microstructure of the corresponding materials were studied by XRD analysis and SEM observation. Elongated α-Sialon grains were observed in the materials sintered
with either Si3N4 starting powders. On the other hand, Si3N4 starting powders with high β phase content resulted in poorer densification
during sintering and the temperature for complete dissolution of β-Si3N4 was 100℃ higher than that for α-Si3N4. The higher the content of β phase in the starting powders, the fewer nucleation sites there were, and the coarser α-Sialon grains were.
A broad size distribution of the Si3N4 starting powders led to the inhomogeneity of α-Sialon grain sizes.

Key words: Ca, α-Sialon, phase formation, microstructure

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