Birefringence and incipient plastic deformation in elastically overdriven [100] CaF2 under shock compression

作者：Li, Y.; Zhou, X. M.^*; Cai, Y.; Liu, C. L.; Luo, S. N.

来源：Journal of Applied Physics, 2018, 123(16): 165901.

DOI：10.1063/1.5023064

• LITHIUM-FLUORIDE
• REFRACTIVE-INDEX
• PRECURSOR DECAY
• CONSTANTS
• SAPPHIRE
• WAVES
• AXIS
• LIF

[100] CaF2 single crystals are shock-compressed via symmetric planar impact, and the flyer plate-target interface velocity histories are measured with a laser displacement interferometry. The shock loading is slightly above the Hugoniot elastic limit to investigate incipient plasticity and its kinetics, and its effects on optical properties and deformation inhomogeneity. Fringe patterns demonstrate different features in modulation of fringe amplitude, including birefringence and complicated modulations. The birefringence is attributed to local lattice rotation accompanying incipient plasticity. Spatially resolved measurements show inhomogeneity in deformation, birefringence, and fringe pattern evolutions, most likely caused by the inhomogeneity associated with lattice rotation and dislocation slip. Transiently overdriven elastic states are observed, and the incubation time for incipient plasticity decreases inversely with increasing overdrive by the elastic shock. Published by AIP Publishing.

• 出版日期2018-4-28
• 单位中国工程物理研究院流体物理研究所; 西南交通大学