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.

用光弹法和蚀坑技术研究了NaCl透明双晶中的裂纹扩展行为及其相关现象。裂纹在{001}解理面上扩展，在裂纹扩展前和扩展过程中沿{011}滑移面形成沿着滑移带。当裂纹尖端靠近晶界时，裂纹扩展变得缓慢，裂纹扩展的阈值应力强度因子KIC^<**>增加。腐蚀坑观察表明，裂纹尖端附近的位错密度在边界附近变得更高。从位错对裂纹尖端的屏蔽作用出发，讨论了晶界对裂纹扩展行为的影响。