Visualization of crack-grain boundary interaction in transparent crystals

透明晶体中裂纹与晶界相互作用的可视化

• 批准号: 08650770
• 负责人: HIGASHIDA Kenji
• 金额: $ 0.32万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08650770/
• 关键词: Fracture; Crack; Grain boundary; Ionic crystal; Dislocation; Shielding; 応力遮蔽(しゃへい)

Crack propagation behavior and its related phenomena in NaCl transparent bicrystals have been investigated by using photoelastic method and etch-pit technique. Crack extension took place on the {001} cleavage plane, and matny slip bands were formed along the {011} slip plane before and during the crack extension. When the crack tip came closer to the grain boundary, crack extension became slower and the threshold stress intensity factor for crack extension KIC^<**> increased. Etch pits observation indicated that the dislocation density around the crack tip became higher near the boundary. The effect of grain boundary on such behavior of crack extension is discussed from the viewpoint of crack tip shielding due to dislocations.

采用光弹性方法和腐蚀坑技术研究了 NaCl 透明双晶中的裂纹扩展行为及其相关现象。裂纹扩展发生在{001}解理面上，并且在裂纹扩展之前和期间沿着{011}滑移面形成了matny滑移带。当裂纹尖端靠近晶界时，裂纹扩展变得更慢，裂纹扩展的阈值应力强度因子 KIC^<**> 增加。蚀坑观察表明，裂纹尖端周围的位错密度在边界附近变高。从位错引起的裂纹尖端屏蔽的角度讨论了晶界对裂纹扩展行为的影响。