不同介质中Si3N4陶瓷的静疲劳与循环疲劳

Static Fatigue and Cyclic Fatigue Behaviour of Si3N4 Ceramics in Different Environment Medias

摘要:

系统研究了Si3N4陶瓷在空气、水、煤油3种介质中的静疲劳及循环疲劳特性。结果发现，在不同介质条件下，循环疲劳的应力腐蚀指数(n)相差不大，且远远低于相同介质条件下静疲劳的应力腐蚀指数。经分析发现，循环载荷部分或全部消除了显微组织屏蔽作用，对材料造成附加损伤，导致其疲劳寿命远远低于静疲劳寿命。

Abstract:

The static fatigue and cyclic fatigue behaviour of Si3N4 ceramics in different environments (air, H2O and kerosene) were studied systematically. The results show that the stress corrosion index(n) under cyclic loading is almost the same in the various medias, and much higher than that in the same media under static loading. Mechanical cycling was deduced to introduce an additional failure mechanism that caused the cyclic fatigue life to be much shorter than static fatigue life.