Characterization of crack growth resistance under thermal shock on silicon nitride with various microstructure
Characterization of crack growth resistance under thermal shock on silicon nitride with various microstructure
复制标题
不同微观结构氮化硅热冲击下裂纹扩展抗力表征
DOI：
10.1299/mej.2014smm0002
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发表时间：
2014
影响因子：
4.4
通讯作者：
T. Akatsu
中科院分区：
文献类型：
--
作者：
T. Sakai;S. Wakayama;Go Kametani;Katsumi Yoshida;T. Akatsu
用自行研制的圆盘棒试验研究了氮化硅在热冲击载荷作用下的抗裂纹扩展性能。利用声发射(AE)技术对热震断裂过程中的微损伤进行了监测。样品由具有针状结构的β-Si3N4组成。在不同温度下烧结了不同显微结构的氮化硅圆柱体。利用诺普压痕引入了预裂裂纹。在圆盘棒试验中，将试件均匀加热到850℃，只用铜棒接触圆形试件的中心进行淬火。在接触后的几分之一秒内，裂纹以不稳定的方式扩展，同时检测到高幅度的声发射信号。随后，观察到了稳定的裂纹扩展，并产生了对应于裂纹扩展的几个低幅度声发射信号。烧结温度越高，裂纹扩展阻力越低。从金相组织观察结果和断裂力学角度考虑，短轴尺寸为-1.5μm的较大晶粒有助于材料的增韧。因此，本研究结果为高抗热震断裂陶瓷材料的开发提供了基本思路。
The crack growth resistance under thermal shock loading on silicon nitride was characterized using Disc-on-Rod test which was developed by the authors. The microdamage during thermal shock fracture was monitored by acoustic emission (AE) technique. Specimens were composed of β-Si3N4 with an acicular structure. Cylinders of silicon nitride with various microstructures were sintered at different temperatures. A pre-crack was introduced using Knoop indentation. In the Disc-on-Rod test, the specimens were uniformly heated to 850 oC, and only the center of circular specimen was quenched by contacting with a copper rod. Within a fraction of a second after contacting, crack propagated in an unstable manner, at the same time, a high amplitude AE signal was detected. Subsequently, stable crack propagation was observed, and several low amplitude AE signals were generated corresponding to crack propagation. The specimen sintered at higher temperature showed lower crack growth resistance. From the results of microstructure observation and the fracture mechanical consideration, it is suggested that larger grains with > 1.5 μm in minor axes contribute to the toughening of materials. Consequently, the results of this study provide fundamental insights for the development of ceramic materials with high resistance to thermal shock fracture.
通过圆盘棒试验对氧化铝陶瓷中的热冲击裂纹扩展行为进行声发射表征
DOI：
--
发表时间：
2005
期刊：
Journal of Acousitc Emission Vol.23
影响因子：
--
作者：
Shuichi WAKAYAMA;Satoshi KOBAYASHI;Toshiya WADA
通讯作者：
Toshiya WADA