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为了比较研究切口角度和深度对氧化锆陶瓷断裂过程中裂纹扩展的影响,本实验制做了尺寸为4.4mm×2.2mm×18mm的氧化锆陶瓷试样,将试样分成6组,每组10个。制备了与试样的长轴方向夹角分别为30°、60°及90°,且深度为1mm和2mm的切口。将试样置于万能力学测试机上加载至断裂后,观察各组试样的断裂曲线,并在体视显微镜下在试样断端的裂纹扩展路径上采点,标注坐标,用origin软件进行曲线拟合。结果显示:当切口角度β=90°时,试样裂纹扩展为纯Ⅰ型;当β=60°时,试样裂纹扩展以Ⅰ型为主;当β=30°时,试样裂纹扩展为Ⅰ-Ⅲ复合型。随着切口深度的增加,切口角度对裂纹扩展方向的影响增加。此外,切口方向对于裂纹的扩展也是一个非常重要的断裂力学参数,随着切口深度的增加,切口角度对裂纹扩展方向的影响增加。
In order to comparatively study the influence of the incision angle and depth on the crack propagation during the fracture of zirconia ceramics, a zirconia ceramic sample with a size of 4.4mm × 2.2mm × 18mm was made in this experiment. The samples were divided into 6 groups of 10 A A notch having an angle of 30 °, 60 ° and 90 ° with respect to the long axis direction of the sample and depths of 1 mm and 2 mm, respectively, was prepared. The specimen was placed on a universal mechanical testing machine loaded to the fracture, observed in each group of specimen fracture curve, and in the stereomicroscope at the end of the crack propagation path at the sampling point, marked coordinates, with the origin software curve Fitting. The results show that when the angle of incision is β = 90 °, the crack propagates to pure type Ⅰ. When β = 60 °, the crack propagation is mainly type Ⅰ. When β = 30 °, the crack propagates to Ⅰ-Ⅲ complex type. As the incision depth increases, the effect of incision angle on crack propagation direction increases. In addition, the notch direction is also a very important fracture mechanics parameter for the crack propagation. As the notch depth increases, the influence of the notch angle on the crack propagation direction increases.