Asymmetric cyclic response of tensile pre-deformed Cu with highly oriented nanoscale twins

doi:10.1016/j.actamat.2019.06.026

IMR OpenIR

	Asymmetric cyclic response of tensile pre-deformed Cu with highly oriented nanoscale twins
	Pan, Qingsong 1; Zhou, Haofei 2,3; Lu, Qiuhong 1; Gao, Huajian 3; Lu, Lei 1
通讯作者	Gao, Huajian(huajian_gao@brown.edu) ; Lu, Lei(Ilu@imr.ac.cn)
	2019-08-15
发表期刊	ACTA MATERIALIA
ISSN	1359-6454
卷号	175 页码:477-486
摘要	History-independent, stable and symmetric cyclic response has been detected in as-deposited bulk polycrystalline Cu with highly oriented nanotwins [Nature 551 (2017) 214-217]. In this study, to deepen the understanding of cyclic deformation in nanotwinned (NT) structures, small levels of tensile pre-strains were applied on NT-Cu, followed by strain-controlled symmetric tension-compression cyclic tests. Distinct from the symmetric cyclic response of as-deposited NT-Cu, the magnitude of the maximum stress in tension is much larger than that of the minimum stress in compression, indicating that the cyclic response of tensile pre-deformed NT-Cu is highly asymmetric. The degree of its cyclic asymmetry gradually decays as the number of cycles or the plastic strain amplitude is increased. The tensile pre-deformed NT-Cu recovers to its symmetric cyclic response after cyclic deformation at sufficiently large plastic strain amplitude, analogous to that detected in as-deposited NT counterparts. Molecular dynamics simulations and microstructural observations revealed that the observed asymmetric cyclic response is mainly related to the activation and movement of threading dislocations with extended misfit dislocation tails lying on the twin boundaries (TBs) during tensile pre-deformation. During cyclic deformation, threading dislocations in adjacent twin interiors tend to link their long tails with one another to form correlated necklace dislocations (CNDs) with a symmetric structure. The CNDs move back-and-forth along the twin boundaries without directional slip resistance, contributing to the transition from asymmetric to symmetric cyclic response of NT-Cu. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
关键词	Nanotwin Pre-strain effect Asymmetric cyclic response Correlated necklace dislocations Fatigue mechanism
资助者	National Science Foundation of China ; Key Research Program of Frontier Science, CAS ; NSF ; Youth Innovation Promotion Association CAS ; Zhejiang University through Hundred Talents Program ; Extreme Science and Engineering Discovery Environment (XSEDE)
DOI	10.1016/j.actamat.2019.06.026
收录类别	SCI
语种	英语
资助项目	National Science Foundation of China[51420105001] ; National Science Foundation of China[51471172] ; National Science Foundation of China[51601196] ; National Science Foundation of China[U1608257] ; Key Research Program of Frontier Science, CAS ; NSF[DMR-1709318] ; Youth Innovation Promotion Association CAS[2019196] ; Zhejiang University through Hundred Talents Program ; Extreme Science and Engineering Discovery Environment (XSEDE)[MS090046]
WOS研究方向	Materials Science ; Metallurgy & Metallurgical Engineering
WOS类目	Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
WOS记录号	WOS:000479023600043
出版者	PERGAMON-ELSEVIER SCIENCE LTD
引用统计	被引频次：16[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/135028
专题	中国科学院金属研究所
通讯作者	Gao, Huajian; Lu, Lei
作者单位	1.Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Liaoning, Peoples R China 2.Zhejiang Univ, Dept Engn Mech, Hangzhou 310027, Zhejiang, Peoples R China 3.Brown Univ, Sch Engn, Providence, RI 02912 USA
推荐引用方式 GB/T 7714	Pan, Qingsong,Zhou, Haofei,Lu, Qiuhong,et al. Asymmetric cyclic response of tensile pre-deformed Cu with highly oriented nanoscale twins[J]. ACTA MATERIALIA,2019,175:477-486.
APA	Pan, Qingsong,Zhou, Haofei,Lu, Qiuhong,Gao, Huajian,&Lu, Lei.(2019).Asymmetric cyclic response of tensile pre-deformed Cu with highly oriented nanoscale twins.ACTA MATERIALIA,175,477-486.
MLA	Pan, Qingsong,et al."Asymmetric cyclic response of tensile pre-deformed Cu with highly oriented nanoscale twins".ACTA MATERIALIA 175(2019):477-486.