IMECH-IR  > 非线性力学国家重点实验室
On strain hardening mechanism in gradient nanostructures
Li JJ; Weng GJ; Chen SH(陈少华); Wu XL(武晓雷); Li, JJ (reprint author), Northwestern Polytech Univ, Sch Mech Civil Engn & Architecture, Dept Engn Mech, Xian 710129, Shaanxi, Peoples R China.
AbstractExperiments have shown that a gradient design, in which grain size spans over four orders of magnitude, can make strong nanomaterials ductile. The enhanced ductility is attributed to the considerable strain hardening capability obtained in the gradient metals. A non-uniform deformation on the lateral sample surface is also observed. This might inject geometrically necessary dislocations (GNDs) into the sample. However, no direct evidence has been provided. Therefore the issues remain: why can the gradient structure generate high strain hardening, and how does it reconcile the strength-ductility synergy of gradient nanostructures? Here for the first time we quantitatively investigate the strain hardening of a gradient interstitial-free steel by developing a dislocation density-based continuum plasticity model, in which the interaction of the component layers in the gradient structure is represented by incorporating GNDs and back stress. It is demonstrated that both the surface non-uniform deformation and the strain-hardening rate up-turn can be quantitatively well predicted. The results also show that the strain hardening rate of the gradient sample can reach as high as that of the coarse-grained counterpart. A strength-ductility map is then plotted, which clearly show that the gradient samples perform much more superior to their homogeneous counterparts in strength-ductility synergy. The predicted map has been verified by a series of experimental data. A detailed analysis on GNDs distribution and back stress evolution at the end further substantiates our view that the good strain hardening capability results from the generation of abundant GNDs by the surface non-uniform deformation into the nano-grained layers of the gradient sample. (C) 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (
KeywordDuctility Dislocations Constitutive Behavior Inhomogeneous Material Analytic Functions
Indexed BySCI ; EI
WOS IDWOS:000389105300005
WOS KeywordDuctility ; Dislocations ; Constitutive behavior ; Inhomogeneous material ; Analytic functions
WOS Research AreaEngineering ; Materials Science ; Mechanics
WOS SubjectEngineering, Mechanical ; Materials Science, Multidisciplinary ; Mechanics
Funding OrganizationAlexander von Humboldt Foundation ; National Natural Science Foundation of China [11402203] ; Fundamental Research Funds for the Central Universities [3102015BJ(II)JGZ025] ; NSF Mechanics of Materials and Structures Program [CMMI-1162431] ; NSFC [11372317, 11532013, 11572328] ; 973 Nano-project [2012CB937500] ; 973 Program [2012CB932203]
Citation statistics
Cited Times:73[WOS]   [WOS Record]     [Related Records in WOS]
Document Type期刊论文
Corresponding AuthorLi, JJ (reprint author), Northwestern Polytech Univ, Sch Mech Civil Engn & Architecture, Dept Engn Mech, Xian 710129, Shaanxi, Peoples R China.
Recommended Citation
GB/T 7714
Li JJ,Weng GJ,Chen SH,et al. On strain hardening mechanism in gradient nanostructures[J]. INTERNATIONAL JOURNAL OF PLASTICITY,2017,88:89-107.
APA Li JJ,Weng GJ,陈少华,武晓雷,&Li, JJ .(2017).On strain hardening mechanism in gradient nanostructures.INTERNATIONAL JOURNAL OF PLASTICITY,88,89-107.
MLA Li JJ,et al."On strain hardening mechanism in gradient nanostructures".INTERNATIONAL JOURNAL OF PLASTICITY 88(2017):89-107.
Files in This Item:
File Name/Size DocType Version Access License
IMCAS-J2016-318.pdf(2968KB)期刊论文作者接受稿开放获取CC BY-NC-SAView Application Full Text
Related Services
Recommend this item
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[Li JJ]'s Articles
[Weng GJ]'s Articles
[陈少华]'s Articles
Baidu academic
Similar articles in Baidu academic
[Li JJ]'s Articles
[Weng GJ]'s Articles
[陈少华]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[Li JJ]'s Articles
[Weng GJ]'s Articles
[陈少华]'s Articles
Terms of Use
No data!
Social Bookmark/Share
File name: IMCAS-J2016-318.pdf
Format: Adobe PDF
All comments (0)
No comment.

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.