| 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.
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| Source Publication | AIP ADVANCES
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| 2015-08-01 | |
| Volume | 5Issue:8Pages:87120 |
| ISSN | 2158-3226 |
| Abstract | 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.; 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. |
| DOI | 10.1063/1.4928448 |
| URL | 查看原文 |
| Indexed By | SCI |
| Language | 英语 |
| WOS ID | WOS:000360655900029 |
| WOS Keyword | MOLECULAR-DYNAMICS SIMULATION ; NANOCRYSTALLINE MATERIALS ; NANOSTRUCTURED METAL ; MAXIMUM STRENGTH ; DUCTILITY ; COPPER ; DISLOCATION ; PLASTICITY ; TOUGHNESS ; STEEL |
| WOS Research Area | Science & Technology - Other Topics ; Materials Science ; Physics |
| WOS Subject | Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Physics, Applied |
| Funding Organization | The 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. |
| Department | LNM材料介观力学性能的表征 |
| Classification | Q3 |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://dspace.imech.ac.cn/handle/311007/55776 |
| Collection | 非线性力学国家重点实验室 |
| Corresponding Author | 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. |
| Affiliation | Chinese 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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| J2015-008.pdf（11833KB） | 期刊论文 | 作者接受稿 | 开放获取 | CC BY-NC-SA | View Download | |
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