【摘要】 本实验采用 LiNbO₃ 单晶,取四种不同晶面指向的样品进行了力学参数,如断裂强度σ_f、断裂功γ_f、断裂韧性 K_Ic和弹性模量 E 的测量。在三点弯曲试验条件下,对 LiNbO₃ 单晶不同取向时的声发射特征也作了研究。实验发现,σ_f、γ_f 和 E 与晶面间距、晶面上的离子排列关系较为明显,声发射信号随单晶的取向不同而变化,这是其各向异性结构所致。更多还原

【Abstract】 The mechanical parameters,such as fracture strength,fracture work,fracturetoughness K_lc and elastic modulus E for LiNbO₃ single crystals with various crys-talline orientations have been determined.The feature of acoustic emission forLiNbO₃ crystal with different orientations under the condition of three points bend-ing testing has been investigated.On the basis of experiments,it has been foundthat the σ_?,γ_? and E parameters are relatively sensible to the distance betweencertain directional planes and also to the arrangement of ions on the crystallineplanes.The feature of acoustic emission can be changed with different crystallineorientations,and this may be caused by anisotropic structure of LiNbO₃ crystal.更多还原