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Atomistic tensile deformation mechanisms of Fe with gradient nano-grained structure
Li, Wenbin; Yuan, Fuping; Wu, Xiaolei; Yuan, FP (reprint author), Chinese Acad Sci, Inst Mech, State Key Lab Nonlinear Mech, 15,North 4th Ring,West Rd, Beijing 100190, Peoples R China.
Source PublicationAIP ADVANCES
2015-08-01
Volume5Issue:8Pages:87120
ISSN2158-3226
AbstractLarge-scale molecular dynamics (MD) simulations have been performed to investigate the tensile properties and the related atomistic deformation mechanisms of the gradient nano-grained (GNG) structure of bcc Fe (gradient grains with d from 25 nm to 105 nm), and comparisons were made with the uniform nano-grained (NG) structure of bcc Fe (grains with d = 25 nm). The grain size gradient in the nano-scale converts the applied uniaxial stress to multi-axial stresses and promotes the dislocation behaviors in the GNG structure, which results in extra hardening and flow strength. Thus, the GNG structure shows slightly higher flow stress at the early plastic deformation stage when compared to the uniform NG structure (even with smaller grain size). In the GNG structure, the dominant deformation mechanisms are closely related to the grain sizes. For grains with d = 25 nm, the deformation mechanisms are dominated by GB migration, grain rotation and grain coalescence although a few dislocations are observed. For grains with d = 54 nm, dislocation nucleation, propagation and formation of dislocation wall near GBs are observed. Moreover, formation of dislocation wall and dislocation pile-up near GBs are observed for grains with d = 105 nm, which is the first observation by MD simulations to our best knowledge. The strain compatibility among different layers with various grain sizes in the GNG structure should promote the dislocation behaviors and the flow stress of the whole structure, and the present results should provide insights to design the microstructures for developing strong-and-ductile metals. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.; Large-scale molecular dynamics (MD) simulations have been performed to investigate the tensile properties and the related atomistic deformation mechanisms of the gradient nano-grained (GNG) structure of bcc Fe (gradient grains with d from 25 nm to 105 nm), and comparisons were made with the uniform nano-grained (NG) structure of bcc Fe (grains with d = 25 nm). The grain size gradient in the nano-scale converts the applied uniaxial stress to multi-axial stresses and promotes the dislocation behaviors in the GNG structure, which results in extra hardening and flow strength. Thus, the GNG structure shows slightly higher flow stress at the early plastic deformation stage when compared to the uniform NG structure (even with smaller grain size). In the GNG structure, the dominant deformation mechanisms are closely related to the grain sizes. For grains with d = 25 nm, the deformation mechanisms are dominated by GB migration, grain rotation and grain coalescence although a few dislocations are observed. For grains with d = 54 nm, dislocation nucleation, propagation and formation of dislocation wall near GBs are observed. Moreover, formation of dislocation wall and dislocation pile-up near GBs are observed for grains with d = 105 nm, which is the first observation by MD simulations to our best knowledge. The strain compatibility among different layers with various grain sizes in the GNG structure should promote the dislocation behaviors and the flow stress of the whole structure, and the present results should provide insights to design the microstructures for developing strong-and-ductile metals. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.
DOI10.1063/1.4928448
URL查看原文
Indexed BySCI
Language英语
WOS IDWOS:000360655900029
WOS KeywordMOLECULAR-DYNAMICS SIMULATION ; NANOCRYSTALLINE MATERIALS ; NANOSTRUCTURED METAL ; MAXIMUM STRENGTH ; DUCTILITY ; COPPER ; DISLOCATION ; PLASTICITY ; TOUGHNESS ; STEEL
WOS Research AreaScience & Technology - Other Topics ; Materials Science ; Physics
WOS SubjectNanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Physics, Applied
Funding OrganizationThe financial supports of this work were provided by the National Key Basic Research Program of China (2012CB932203 and 2012CB937500) and NSFC (11222224, 11472286, and 11021262). The simulations reported here were performed at Supercomputing Center of Chinese Academy of Sciences.
DepartmentLNM材料介观力学性能的表征
ClassificationQ3
Citation statistics
Cited Times:9[WOS]   [WOS Record]     [Related Records in WOS]
Document Type期刊论文
Identifierhttp://dspace.imech.ac.cn/handle/311007/55776
Collection非线性力学国家重点实验室
Corresponding AuthorYuan, FP (reprint author), Chinese Acad Sci, Inst Mech, State Key Lab Nonlinear Mech, 15,North 4th Ring,West Rd, Beijing 100190, Peoples R China.
AffiliationChinese Acad Sci, Inst Mech, State Key Lab Nonlinear Mech, Beijing 100190, Peoples R China
Recommended Citation
GB/T 7714
Li, Wenbin,Yuan, Fuping,Wu, Xiaolei,et al. Atomistic tensile deformation mechanisms of Fe with gradient nano-grained structure[J]. AIP ADVANCES,2015,5(8):87120.
APA Li, Wenbin,Yuan, Fuping,Wu, Xiaolei,&Yuan, FP .(2015).Atomistic tensile deformation mechanisms of Fe with gradient nano-grained structure.AIP ADVANCES,5(8),87120.
MLA Li, Wenbin,et al."Atomistic tensile deformation mechanisms of Fe with gradient nano-grained structure".AIP ADVANCES 5.8(2015):87120.
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