Mechanical characteristics of sapphire before and after neutron irradiation

Sapphire crystal is irradiated by neutron flux with the fluence of 1.0×1018 n/cm2 and 1.0×1019 n/cm2. The influence of neutron irradiation on the mechanical properties of sapphire is investigated in this paper. The crystal structure of sapphire is investigated by double-crystal X-ray diffraction (DXRD) and transmission electron microscopy (TEM). Compared with the pristine sapphire, the elastic modulus is decreased and the Vickers hardness, fracture toughness and biaxial flexure strength are increased in the neutron irradiated sample. The elastic modulus, Vickers hardness, fracture toughness and biaxial flexural strength of the 1.0×1019 n/cm2 neutron irradiated sapphire are 497.11 GPa (at room temperature), 18.8 GPa, 2.95 MPa m1/2 and 604 MPa (600 °C), respectively.