Fracture‐Strength Anisotropy of Sapphire
Fracture‐Strength Anisotropy of Sapphire
复制标题
蓝宝石断裂强度各向异性
DOI：
10.1111/j.1151-2916.1976.tb09390.x
复制
发表时间：
1976
影响因子：
3.9
通讯作者：
P. Becker
中科院分区：
文献类型：
--
作者：
P. Becker
At 22°C, the bend strength of as-ground sapphire bars with different orientations of tensile surface and tensile axis varies from 4×104 to 12×104 psi as a result of the anisotropies of machining damage and fracture energy. Generally, the strength-controlling surface flaws caused by grinding are of constant size; failure from such flaws is affected by grinding-induced slip and twinning. Surface striations, which occur when there is negligible subsurface slip, can lead to stress concentrations, whereas twins can lead to increases in flaw size; each of these effects reduces strength. In addition, the large anisotropy in fracture strength, which is not predicted by the elastic anisotropy, is controlled by the anisotropic fracture energy. Approximation of the attractive forces across the fracture plane based on elastic moduli and interplanar distance can be used to understand the fracture energy anisotropy.
