Correlated necklace dislocations in highly oriented nanotwinned metals

作     者：Haofei ZHOU Pan-pan ZHU Haofei ZHOU;Pan-pan ZHU

作者机构：Center for X-mechanicsDepartment of Engineering MechanicsZhejiang UniversityHangzhou 310058China 

出 版 物：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 (浙江大学学报（英文版）A辑（应用物理与工程）)

年 卷 期：2020年第21卷第4期

页      面：294-303页

核心收录：

学科分类：07[理学] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 080102[工学-固体力学] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：Project supported by the National Natural Science Foundation of China(No.11902289) the Hundred Talents Program of Zhejiang University,China 

主　　题：Nanotwinned(NT) metals Correlated necklace dislocation(CND) Twin boundary(TB) Size effect Cyclic response 

摘      要：In this paper, we review recent progress in the understanding of a novel dislocation mechanism, named correlated necklace dislocations(CNDs), activated in highly oriented nanotwinned(NT) metals under monotonic and cyclic loading applied parallel to the twin boundaries(TBs). This mechanism was initially revealed to be responsible for the continuous strengthening behavior of NT metals when the TB spacing(λ) is reduced to around 1 nm. It was later found that the presence of a crack-like defect could trigger the operation of CNDs at much larger TB spacings. Most recently, atomistic modeling and experiments demonstrated a history-independent and stable cyclic response of highly oriented NT metals governed by CNDs formed in the NT structure under cyclic loading. CNDs move along the twin planes without directional lattice slip resistance, thus contributing to a symmetric cyclic response of the NT structure regardless of pre-strains imposed on the sample before cyclic loading. We conclude with potential research directions in the investigation of this unique deformation mechanism in highly oriented NT metals.