Atomistic simulation study of tensile deformation in bulk nanocrystalline bcc iron

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	Atomistic simulation study of tensile deformation in bulk nanocrystalline bcc iron
	Yuan FP(袁福平); Yuan, FP
刊名	SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
	2012-09-01
通讯作者邮箱	fpyuan@lnm.imech.ac.cn
卷号	55 期号:9 页码:1657-1663
关键词	molecular dynamics simulation phase transformation dislocation activities grain boundary diffusion iron Grain-Boundary Diffusion Molecular-Dynamics Mechanical-Behavior High-Pressure Fcc Metals Dislocations Transition Nucleation Strength Aluminum
ISSN号	1674-7348
通讯作者	Yuan, FP ; Chinese Acad Sci, State Key Lab Nonlinear Mech, Inst Mech, Beijing 100190, Peoples R China.
产权排序	Chinese Acad Sci, State Key Lab Nonlinear Mech, Inst Mech, Beijing 100190, Peoples R China
中文摘要	In the present work, the mechanical properties of bulk nanocrystalline (NC) bcc Fe under tensile deformation have been studied by molecular dynamics (MD) simulations. Average flow stress was found to decrease with grain refinement below 13.54 nm, indicating a breakdown in the Hall-Petch relation. A change from grain boundary (GB) mediated dislocation activities to GB activities may be a possible explanation of the breakdown in the Hall-Petch relation. The results also indicate that the average flow stress increases with increasing strain rates and decreasing temperatures. Stress induced phase transformations were observed during the tensile deformation of NC Fe, and such phase transformations were found to be reversible with respect to the applied stress. The maximum fraction of the cp atoms was also found to increase with increasing applied stress. Significant phase transformation occurred in the stacking fault zone due to dislocation activities for large grain size (13.54 nm), while significant phase transformation occurred in the GBs due to GB activities for small grain size (3.39 nm). At deformation temperature of 900 K and above, no apparent phase transformation occurred because all atoms at GBs and grain interior could easily rearrange their position by thermal activation to form local vacancies/disordered structures rather than ordered close packed (cp) structures.
学科主题	损伤、破坏机理和微结构演化
分类号	二类/Q3
收录类别	SCI ; EI
资助信息	This work was supported by the National Basic Research Program of China (Grant Nos. 2012CB932203 and 2012CB937500) and the National Natural Science Foundation of China (Grants No. 11002151, 10721202 and 11072243).
原文出处	http://dx.doi.org/10.1007/s11433-012-4830-6
语种	英语
WOS记录号	WOS:000307719500021
公开日期	2013-01-18
内容类型	期刊论文
源URL	[http://dspace.imech.ac.cn/handle/311007/46671]
专题	力学研究所_非线性力学国家重点实验室
通讯作者	Yuan, FP
推荐引用方式 GB/T 7714	Yuan FP,Yuan, FP. Atomistic simulation study of tensile deformation in bulk nanocrystalline bcc iron[J]. SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY,2012,55(9):1657-1663.
APA	袁福平,&Yuan, FP.(2012).Atomistic simulation study of tensile deformation in bulk nanocrystalline bcc iron.SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY,55(9),1657-1663.
MLA	袁福平,et al."Atomistic simulation study of tensile deformation in bulk nanocrystalline bcc iron".SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY 55.9(2012):1657-1663.