ZrO_2陶瓷材料在水环境中的疲劳断裂特性

Fatigue Fracture Behavior of Zirconia Ceramic in Water Environment

采用断裂力学中的四点弯曲试验法 ,对 Zr O_2 陶瓷材料分别在大气、水环境中的静疲劳和循环疲劳破坏特性进行研究 ,通过扫描电子显微镜 (SEM)对试验片断裂面的微细组织进行观察 ,分析并阐明了造成材料疲劳断裂的机理 .结果表明 ,相同应力条件下 ,材料在水环境中的疲劳寿命比大气环境中低以及循环疲劳对材料的疲劳寿命起到劣化作用 ,该劣化作用可以认为是由于循环应力使得微裂纹增加和扩展造成的 .

The characteristics of static and cyclic fatigue fracture were studied by the crack growth test using the four point bending method in the environments of both air and water for zirconia ceramic. The mechanism of the fatigue fracture was analyzed by the observations of fracture surfaces with scanning electron microscopy (SEM). The decrease in the fatigue lifetime due to water environment and cyclic loading is clearly observed. The effect of cyclic loading seems to be due to the increase and expansion of the microcracks by the cyclic loading.