| Shock response of nanotwinned copper from large-scale molecular dynamics simulations | |
Yuan FP(袁福平) ; Wu XL(武晓雷); Yuan, FP; Chinese Acad Sci, State Key Lab Nonlinear Mech, Inst Mech, Beijing 100190, Peoples R China.
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| Source Publication | PHYSICAL REVIEW B
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| 2012-10-10 | |
| Volume | 86Issue:13Pages:134108 |
| ISSN | 1098-0121 |
| Abstract | A series of large-scale molecular dynamics simulations have been performed to investigate the shock response of nanotwinned (NT) Cu, including shock-induced plasticity, strength behind the shock front, and spall behaviors. In this study, two configurations were investigated at an impact velocity of 600m/s, i.e., the practical NT polycrystalline Cu with an average grain size of 10 nm and the simple NT single-crystalline Cu with an impact direction of [11 (2) over bar]. In the NT polycrystalline Cu, the average flow stress behind the shock front first increases with decreasing twin-boundary spacing (TBS), reaching a maximum at a critical TBS, and then decreases as the TBS become even smaller. This trend of the average flow stress with decreasing TBS is due to two competitive dislocation activities under shock loading, with one being inclined to the twin boundaries (the dislocation-twin boundary intersecting) and the other parallel to the twin boundaries (detwinning with twin-boundary migration). Since voids always nucleate near the grain boundary (GB) junctions and then grow along the GBs to create spallation, no apparent correlation between the spall strength and TBS is observed in the NT polycrystalline Cu. However, the spall strengths of the NT single-crystalline Cu are found to increase with decreasing TBS. Two partial dislocation slips initiated from each twin boundary create voids at the intersections between the partial dislocation slips and twin boundaries. The smaller TBSs result in a larger number of twin boundaries and provide more nucleation sites for voids, requiring a higher tensile stress to create spallation in the NT single-crystalline Cu. These findings should provide insights for understanding the deformation physics of the NT metals subjected to shock loading. |
| Keyword | Nanocrystalline Materials Ultrahigh Strength Maximum Strength Fcc Metals Deformation Twin Compression Ductility Crystals Single |
| Subject Area | 损伤、破坏机理和微结构演化 |
| URL | 查看原文 |
| Indexed By | SCI |
| Language | 英语 |
| WOS ID | WOS:000309651000001 |
| Funding Organization | The authors would like to acknowledge the financial support of 973 Program of China (Grants No. 2012CB932203, No. 2012CB937500, and No. 2010CB631004) and NSFC (Grants No. 11002151, No. 11222224, and No. 11072243). |
| Department | LNM材料介观力学性能的表征 |
| Classification | 二类/Q1 |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://dspace.imech.ac.cn/handle/311007/46718 |
| Collection | 非线性力学国家重点实验室 |
| Corresponding Author | Yuan, FP; Chinese Acad Sci, State Key Lab Nonlinear Mech, Inst Mech, Beijing 100190, Peoples R China. |
| Recommended Citation GB/T 7714 | Yuan FP,Wu XL,Yuan, FP,et al. Shock response of nanotwinned copper from large-scale molecular dynamics simulations[J]. PHYSICAL REVIEW B,2012,86,13,:134108. |
| APA | 袁福平,武晓雷,Yuan, FP,&Chinese Acad Sci, State Key Lab Nonlinear Mech, Inst Mech, Beijing 100190, Peoples R China..(2012).Shock response of nanotwinned copper from large-scale molecular dynamics simulations.PHYSICAL REVIEW B,86(13),134108. |
| MLA | 袁福平,et al."Shock response of nanotwinned copper from large-scale molecular dynamics simulations".PHYSICAL REVIEW B 86.13(2012):134108. |
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