Crack-healing behavior of Si3N4/SiC composite under stress and low oxygen pressure
Crack-healing behavior of Si3N4/SiC composite under stress and low oxygen pressure
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DOI：
10.1016/j.msea.2010.02.060
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发表时间：
2010-06
期刊：
影响因子：
6.4
通讯作者：
Koji Takahashi;Y. Jung;Yasuto Nagoshi;K. Ando
中科院分区：
文献类型：
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作者：
Koji Takahashi;Y. Jung;Yasuto Nagoshi;K. Ando
研究了Si3N4/SiC复合材料在恒定应力和低氧分压下的裂纹愈合行为。采用压痕法在拉伸表面中心引入长度约100μm的半椭圆形表面裂纹。试件在拉应力（σapp.=200-300MPa）、低氧分压和空气（[公式：见正文]）下于1200℃、5h进行裂纹愈合。裂纹愈合阈值恒定应力定义为氧分压超过500Pa时200MPa。 [式：见正文]中拉应力作用下裂纹愈合试件的弯曲强度与光滑愈合试件几乎相同，且大多数试件在裂纹愈合区外断裂。从这些结果中，我们得出结论，在低氧压力下的应力下可以实现裂纹愈合，并且可以延长 Si3N4/SiC 复合陶瓷的使用寿命并提高可靠性。
The crack-healing behavior of Si3N4/SiC composite under constant stress and low oxygen partial pressure was investigated. A semi-elliptical surface crack with a length of about 100μm was introduced at the center of the tensile surface by the indentation method. The specimens were crack-healed at 1200°C for 5h under tensile stress (σapp.=200–300MPa) and under low oxygen partial pressure and air ( [Formula: see text] ). The threshold constant stress for crack-healing was defined as 200MPa in oxygen partial pressure over 500Pa. The bending strengths of crack-healed specimens under tensile stress in [Formula: see text] showed almost the same value as a healed smooth specimen, and most specimens fractured outside the crack-healed zone. From these results, we conclude that crack-healing can be achieved under stress in low oxygen pressure and can lengthen lifetime and increase reliability in Si3N4/SiC composite ceramic.