Fracture‐Strength Anisotropy of Sapphire

摘要: At 22°C, the bend strength of as-ground sapphire bars with different orientations tensile surface and axis varies from 4×104 to 12×104 psi as a result anisotropies machining damage fracture energy. Generally, strength-controlling flaws caused by grinding are constant size; failure such is affected grinding-induced slip twinning. Surface striations, which occur when there negligible subsurface slip, can lead stress concentrations, whereas twins increases in flaw each these effects reduces strength. In addition, large anisotropy strength, not predicted elastic anisotropy, controlled anisotropic Approximation attractive forces across plane based on moduli interplanar distance be used understand energy anisotropy.