High-order hierarchical nanotwins with superior strength and ductility

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	High-order hierarchical nanotwins with superior strength and ductility
	Liu, XW; Sun, LG; Zhu, LL; Liu, JB; Lu, K; Lu, J; Lu, J (reprint author), City Univ Hong Kong, Natl Precious Met Mat Engn Res Ctr, Hong Kong Branch, Kowloon, Hong Kong, Peoples R China.
刊名	ACTA MATERIALIA
	2018-05-01
卷号	149 页码:397-406
关键词	Centered-cubic Metals Mechanical-properties Nanocrystalline Materials Molecular-dynamics Grain-size Deformation Silver Copper Temperature Plasticity
ISSN号	1359-6454
英文摘要	Microstructures dominate the mechanical properties of metals because of the interactions of dislocations and other defects. Hierarchical nanotwins (HNTs) in different orientations/orders are more effective in interacting with dislocations, which will enhance the mechanical properties of materials. However, the confirmation of high-order HNTs (>2) has not been formally established to fully explore the potential of mechanical property enhancement of HNT structured materials. In this work, HNTs up to five orders with sequential identification in pure silver (Ag) were fabricated by combining the techniques of surface mechanical attrition treatment and uniaxial pre-loading. The strength of this high-order HNT-structured Ag has been improved by over three times without sacrificing ductility. In addition, compared to other structures, the HNT structure can increase the limit of strength of the materials at high ductility. By performing in situ transmission electron microscopy, the HNT generation mechanism is revealed in real time, and the generation conditions of stable HNTs are established. Molecular dynamic simulations present the structure evolution details of HNTs at atomic scale, and the dislocation-based theory unveils the underlying mechanism. By using this generic approach, high-order HNT (>= 5) structures can be achieved in crystalline materials. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.; Microstructures dominate the mechanical properties of metals because of the interactions of dislocations and other defects. Hierarchical nanotwins (HNTs) in different orientations/orders are more effective in interacting with dislocations, which will enhance the mechanical properties of materials. However, the confirmation of high-order HNTs (>2) has not been formally established to fully explore the potential of mechanical property enhancement of HNT structured materials. In this work, HNTs up to five orders with sequential identification in pure silver (Ag) were fabricated by combining the techniques of surface mechanical attrition treatment and uniaxial pre-loading. The strength of this high-order HNT-structured Ag has been improved by over three times without sacrificing ductility. In addition, compared to other structures, the HNT structure can increase the limit of strength of the materials at high ductility. By performing in situ transmission electron microscopy, the HNT generation mechanism is revealed in real time, and the generation conditions of stable HNTs are established. Molecular dynamic simulations present the structure evolution details of HNTs at atomic scale, and the dislocation-based theory unveils the underlying mechanism. By using this generic approach, high-order HNT (>= 5) structures can be achieved in crystalline materials. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
学科主题	Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
语种	英语
资助机构	National Key R&D Program of China [2017YFA0204403]; RGC Hong Kong General Research Fund [CityU 11247516]; National Natural Science Foundation of China [51590892, 11472243, 11621062]; Hong Kong Innovation and Technology Commission via the Hong Kong Branch of National Precious Metals Material Engineering Research Center [9448003]; Guangdong Science and Technology Department [2014B050504003]; Technology Innovation Commission of Shenzhen Municipality [SZSTI JCYJ20150601102053069, SZSTI ZDSYS201602291653165]; Shenzhen Virtual University Park [R-IND1710]; Shenzhen Science Technology and Innovation Commission [JSGG 20141020103826038]; Fundamental Research Funds for the Central Universities
公开日期	2018-06-05
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/79328]
专题	金属研究所_中国科学院金属研究所
通讯作者	Lu, J (reprint author), City Univ Hong Kong, Natl Precious Met Mat Engn Res Ctr, Hong Kong Branch, Kowloon, Hong Kong, Peoples R China.
推荐引用方式 GB/T 7714	Liu, XW,Sun, LG,Zhu, LL,et al. High-order hierarchical nanotwins with superior strength and ductility[J]. ACTA MATERIALIA,2018,149:397-406.
APA	Liu, XW.,Sun, LG.,Zhu, LL.,Liu, JB.,Lu, K.,...&Lu, J .(2018).High-order hierarchical nanotwins with superior strength and ductility.ACTA MATERIALIA,149,397-406.
MLA	Liu, XW,et al."High-order hierarchical nanotwins with superior strength and ductility".ACTA MATERIALIA 149(2018):397-406.