Measurement of Crack Tip Toughness in Alumina as a Function of Grain Size
Measurement of Crack Tip Toughness in Alumina as a Function of Grain Size
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氧化铝裂纹尖端韧性随晶粒尺寸变化的测量
DOI：
10.1111/j.1151-2916.1997.tb02848.x
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发表时间：
2005
影响因子：
3.9
通讯作者：
J. Rödel
中科院分区：
文献类型：
--
作者：
J. Seidel;J. Rödel
利用扫描电镜对裂纹尖端附近的裂纹轮廓进行测量，测量了氧化铝裂纹尖端韧性随晶粒尺寸（平均晶粒尺寸0.9 ~ 16 μm）的变化规律。为了进行对比试验，本研究中包括了两种裂缝形态：加载了原位装置的直裂缝（CT试样）；和径向压痕裂纹。测量的裂纹尖端韧性值与裂纹几何形状无关，也与晶粒尺寸无关。裂纹尖端韧性平均为2.3 mpam /2。由裂纹轮廓测量确定的裂纹尖端韧性明显低于用常规压痕技术评估的韧性（例如，压痕强度弯曲）。
Crack profile measurements near the crack tip in the SEM were used to measure crack tip toughness of alumina as a function of grain size (average grain size 0.9–16 μm). For comparative tests, two crack configurations were included in the present study: straight cracks (CT specimen) loaded with an in situ device; and radial indentation cracks. The measured crack tip toughness values were independent of crack geometry, and no grain size dependence could be discerned. A mean crack tip toughness of 2.3 MPam1/2 was evaluated. The crack tip toughness determined from crack profile measurements is significantly lower than the toughness evaluated with conventional indentation techniques (e.g., indentation strength bending).