Size-dependent plastic deformation and failure mechanisms of nanotwinned Ni3Al: Insights from an atomistic cracking model

doi:10.1016/j.msea.2015.10.006

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	Size-dependent plastic deformation and failure mechanisms of nanotwinned Ni3Al: Insights from an atomistic cracking model
	Wang YJ; Tsuchiya K; Dai LH(戴兰宏); Wang, YJ (reprint author), Chinese Acad Sci, Inst Mech, State Key Lab Nonlinear Mech, Beijing 100190, Peoples R China.
发表期刊	MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
	2016-01
卷号	649 页码:449-460
ISSN	0921-5093
摘要	The polycrystalline Ni3Al is brittle since the notorious intergranular fracture mode hinders its applications. Here we perform molecular dynamics to highlight the unique role of nanotwin boundary in the plastic deformation and failure mechanisms of Ni3Al via an atomistic cracking model. Surprisingly, the strength, ductility and fracture toughness of the nanotwinned Ni3Al are revealed to increase simultaneously with reducing twin size, possibly evading a traditional tradeoff between ductility/toughness and strength. A possible quasi-brittle fracture mode in single crystalline Ni3Al is recognized as nucleating twinning partials from crack tip. However, the pre-existing twin boundaries can suppress the emission and propagation of successive twinning dislocations. Instead, dislocation avalanches happen and serve as a crack blunting mechanism which leads to the ductile fracture pattern of the nanotwinned Ni3Al. A sizedependent transition of fracture mode from dislocation nucleation to shear localization is observed as twin becomes very small. A physical model combined with energetics analysis is provided to rationalize the transition. Our atomistic insights are in qualitative agreement with recent observations of improved strength and ductility of Ni3Al with disordered nanotwinned structure after severe plastic deformation. (C) 2015 Elsevier B.V. All rights reserved.
关键词	Nanostructured Materials Twinning Crystal Plasticity Fracture Atomistic Simulations
DOI	10.1016/j.msea.2015.10.006
URL	查看原文
收录类别	SCI ; EI
语种	英语
WOS记录号	WOS:000364796400051
关键词[WOS]	MOLECULAR-DYNAMICS METHOD ; HIGH-PRESSURE TORSION ; NANOCRYSTALLINE MATERIALS ; FRACTURE-TOUGHNESS ; ULTRAHIGH STRENGTH ; MAXIMUM STRENGTH ; SHAPE-MEMORY ; METALS ; DUCTILITY ; HARDNESS
WOS研究方向	Science & Technology - Other Topics ; Materials Science ; Metallurgy & Metallurgical Engineering
WOS类目	Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
项目资助者	This work is financially supported by the NSFC (Nos. 11132011, 11402269, and 11472287), the National Key Basic Research Program of China (No. 2012CB937500), and the CAS/SAFEA International Partnership Program for Creative Research Teams.
课题组名称	LNM冲击动力学与新型材料力学性能
论文分区	一类
力学所作者排名	True
引用统计	被引频次：18[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://dspace.imech.ac.cn/handle/311007/58381
专题	非线性力学国家重点实验室
通讯作者	Wang, YJ (reprint author), Chinese Acad Sci, Inst Mech, State Key Lab Nonlinear Mech, Beijing 100190, Peoples R China.
推荐引用方式 GB/T 7714	Wang YJ,Tsuchiya K,Dai LH,et al. Size-dependent plastic deformation and failure mechanisms of nanotwinned Ni3Al: Insights from an atomistic cracking model[J]. MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,2016,649:449-460.
APA	Wang YJ,Tsuchiya K,Dai LH,&Wang, YJ .(2016).Size-dependent plastic deformation and failure mechanisms of nanotwinned Ni3Al: Insights from an atomistic cracking model.MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,649,449-460.
MLA	Wang YJ,et al."Size-dependent plastic deformation and failure mechanisms of nanotwinned Ni3Al: Insights from an atomistic cracking model".MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING 649(2016):449-460.

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