Observing Dislocations Transported by Twin Boundaries in Al Thin Film: Unusual Pathways for Dislocation-Twin Boundary Interactions

被引：11

作者：

Kou, Zongde ^{[1
]}

Feng, Tao ^{[1
]}

Lan, Si ^{[1
]}

Tang, Song ^{[1
]}

Yang, Lixia ^{[4
]}

Yang, Yanqing ^{[2
]}

Wilde, Gerhard ^{[1
,3
]}

机构：

[1] Nanjing Univ Sci & Technol, Herbert Gleiter Inst Nanosci, Sch Mat Sci & Engn, Nanjing 210094, Peoples R China

[2] Northwestern Polytech Univ, State Key Lab Solidificat Proc, Xian 710072, Peoples R China

[3] Univ Munster, Inst Mat Phys, D-48149 Munster, Germany

[4] Nanjing Univ Aeronaut & Astronaut, Coll Mat Sci & Technol, Nanjing 210016, Peoples R China

来源：

NANO LETTERS | 2022年 / 22卷 / 15期

基金：

中国国家自然科学基金; 中国博士后科学基金;

关键词：

Dislocation; twin; Al; crack tip; in situ transmission electron microscopy; LATTICE DISLOCATIONS; ULTRAHIGH STRENGTH; FREE ZONE; IN-SITU; DEFORMATION; MECHANISMS; DEFECTS; DUCTILITY; TEM;

D O I：

10.1021/acs.nanolett.2c01763

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Twins are generally regarded as obstacles to dislocations in face-centered cubic metals and can modify individual dislocations by locking them in twin boundaries or obliging them to dissociate. Through in situ tensile experiments on Al thin film in a transmission electron microscope, we report a dynamic process of dislocations being transported by twin lamella via periodic twinning and detwinning at the atomic scale. Following this process, a 60 degrees dislocation first transforms into a sessile step of the twin boundary, then migrates under stress as a step and finally reverts back into a 60 degrees dislocation. Our results reveal a novel evolution route of dislocations by a dislocation-twin interaction where the twins act as transport vehicles rather than as obstacles. The potential implications of this mechanism on toughening are also discussed.

引用

页码：6229 / 6234

页数：6

共 40 条

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