无机材料学报

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Y-α/β-Sialon陶瓷材料及疲劳特性研究

邬凤英; 詹国栋; 庄汉锐; 来亭荣   

  1. 中国科学院上海硅酸盐研究所; 上海 200050

  • 收稿日期:1996-06-25 修回日期:1996-08-22 出版日期:1997-08-20 网络出版日期:1997-08-20

Y-α/β-Sialon Ceramics and Its Fatigue Behavior

WU Fengying; ZHAN Guodong; ZHUANG Hanrui; LAI Tingrong   

  1. Shanyhai Institute of Ceramics; Chinese Academy of Sciences Shanghai 200050 China
  • Received:1996-06-25 Revised:1996-08-22 Published:1997-08-20 Online:1997-08-20

摘要: 本文通过组份设计,选用Si3N4、AIN和Y2O3等粉末为原料,在1800~1950℃进行气氛加压烧结(GPS),制备了性能优良的Y-α/β-Sialon陶瓷材料;利用XRD、EDAX和HREM详细地研究了相组成和晶界特性,其主晶相为β-Sialon和α-Sialon,晶界由少量的J-Y4Si2O7N2结晶相以及微量的玻璃相构成;并进一步探讨了材料在循环疲劳载荷下Vickers压痕短裂纹扩展特性,结果表明,最大应力强度因子与裂纹扩展速率之间呈V型扩展行为,并对外加应力水平非常敏感.

关键词: Sialon, GPS, 显微结构, Vickers压痕, 循环疲劳裂纹扩展

Abstract: The investigations were mainly focused on the phase composition, microstructure and fatigue behavior of fully-dense Y-α/β-Sialon
ceramics prepared from powder mixtures of Si3N4, AlN and Y2O3 by using gas pressure sintering technique.

The results obtained show that the typical microstructure of mixed Y-α/β-Sialon ceramics consists of needle-like grains of the β-phase and equi-axed α-Sialon grains
with a small amount of glassy phase and J-Y4Si2O7N2[102] crystalline phase on grain boundaries.

The cyclic fatigue crack growth behavior from microindentation flaws was investiated with gas pressure sintered Y-α/β-Sialon ceramics, A V-shape behavior was observed in the relation between the maximum applied stress intensity factor and crack
growth rates which are sensitive to the level of applied stresses.

Key words: Sialon, GPS, microstructure, vickers indentation, cyclic fatigue crack growth