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高温等静压后处理液相烧结SiC陶瓷的结构与性能表征

董绍明; 陈忠明; 谭寿洪; 江东亮; 郭景坤   

  1. 中国科学院上海硅酸盐研究所; 上海 200050
  • 收稿日期:1996-11-12 修回日期:1997-01-13 出版日期:1997-12-20 网络出版日期:1997-12-20

Characterization of Microstructure and Properties of Post-hot Isostatic Pressing of Liquid Phase Sintered SiC

DONG Shaoming; CHEN Zhongming; TAN Shouhong; JIANG Dongliang; GUO Jingkun   

  1. Shanghai Institute of Ceratnics; Chinese Academy of Sciences Shanghai 200050 China
  • Received:1996-11-12 Revised:1997-01-13 Published:1997-12-20 Online:1997-12-20

摘要: 本文研究了高温等静压(HIP)后处理工艺对液相烧结SiC陶瓷的显微结构及力学性能的影响.实验表明,HIP后处理的效果随烧结助剂的不同及液相烧结温度的变化而改变.Ar气氛条件下的HIP后处理可以提高液相烧结SiC的密度,减少或消除内部气孔等结构缺陷,但不引起晶粒的长大.N2条件下的HIP后处理除了具有Ar-HIP后处理的优点外,由于表面SiC与N2之间的反应生成的Si3N4可以有效地改善表面状态,从而达到表面改性,提高SiC陶瓷的力学性能.结构分析表明,经N2-HIP后处理,表面氮化层中晶粒细小,结构致密.同时,HIP后处理的效果还受液相烧结SiC陶瓷显微结构的影响,当液相烧结SiC的烧结温度较低,晶粒较细时,经HIP后处理,尤其是N2-HIP后处理,强度和韧性均有较大幅度的提高.

关键词: 液相烧结, SiC, 高温等静压后处理, 显微结构, 力学性能

Abstract: The microstructure and mechanical properties of liquid phase sintered SiC followed by post-hot isostatic pressing (HIP) were studied. It is indicated that the effect of post-HIP treatment is changed with the variation of
sintering aids and temperature of liquid phase sintering. After Ar-HIP treatment, the density of SiC is increased and the inside pores are
diminished, but grain growth is depressed. Besides the advantages of the Ar-HIP, N2-HIP can modify the surface state because of the reaction
between SiC and N2 so that the mechanical properties are improved. Microstructure analysis has shown that after N2-HIP treatment,
grain size is decreased and the density is increased. Meanwhile, the results of post-HIP treatment are highly affected by the microstructure
of the liquid phase sintered SiC. When the sintering temperature is relatively lower and the grain size is smaller, after post-HIP treatment, esp.
N2-HIP treatment, bending strength and fracture toughness of the liquid phase sintered SiC are improved greatly.

Key words: liquid phase sintering, SiC, post-hot isostatic pressing, microstructure, properties