| Time, stress, and temperature-dependent deformation in nanostructured copper: Stress relaxation tests and simulations | |
| Yang XS; Wang YJ(王云江); Wang GY; Zhai HR; Dai LH(戴兰宏); Zhang TY; Zhang, TY (reprint author), Shanghai Univ, Mat Genome Inst, 99 Shangda Rd, Shanghai 200444, Peoples R China. | |
| Source Publication | ACTA MATERIALIA
 |
| 2016 | |
| Volume | 108Pages:252-263 |
| ISSN | 1359-6454 |
| Abstract | In the present work, stress relaxation tests, high-resolution transmission electron microscopy (HRTEM), and molecular dynamics (MD) simulations were conducted on coarse-grained (cg), nanograined (ng), and nanotwinned (nt) copper at temperatures of 22 degrees C (RT), 30 degrees C, 40 degrees C, 50 degrees C, and 75 degrees C. The comprehensive investigations provide sufficient information for the building-up of a formula to describe the time, stress, and temperature-dependent deformation and clarify the relationship among the strain rate sensitivity parameter, stress exponent, and activation volume. The typically experimental curves of logarithmic plastic strain rate versus stress exhibited a three staged relaxation process from a linear high stress relaxation region to a subsequent nonlinear stress relaxation region and finally to a linear low stress relaxation region, which only showed-up at the test temperatures higher than 22 degrees C, 22 degrees C, and 30 degrees C, respectively, in the tested cg-, ng-, and nt-Cu specimens. The values of stress exponent, stress independent activation energy, and activation volume were determined from the experimental data in the two linear regions. The determined activation parameters, HRTEM images, and MD simulations consistently suggest that dislocation-mediated plastic deformation is predominant in all tested cg-, ng-, and nt-Cu specimens in the initial linear high stress relaxation region at the five relaxation temperatures, whereas in the linear low stress relaxation region, the grain boundary (GB) diffusion-associated deformation is dominant in the ng- and cg-Cu specimens, while twin boundary (TB) migration, i.e., twinning and detwinning with parallel partial dislocations, governs the time, stress, and temperature-dependent deformation in the nt-Cu specimens. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
| Keyword | Stress Relaxation Nanotwin Copper Hrtem Atomistic Simulations |
| DOI | 10.1016/j.actamat.2016.02.021 |
| URL | 查看原文 |
| Indexed By | SCI ; EI |
| Language | 英语 |
| WOS ID | WOS:000374072700024 |
| WOS Keyword | Stress relaxation ; Nanotwin ; Copper ; HRTEM ; Atomistic simulations |
| WOS Research Area | Materials Science ; Metallurgy & Metallurgical Engineering |
| WOS Subject | Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering |
| Funding Organization | This work was supported by the General Research Fund (Project number, 622911) from the Hong Kong Research Grants Council. T.Y.Z. is grateful for the financial support by the research grant (No.14DZ2261200) from the Science and Technology Commission of Shanghai Municipality. Y.J.W and L.H.D acknowledge the financial supports from the NSFC (Nos. 11132011, 11402269, 11472287), the National Key Basic Research Program of China (No. 2012CB937500), and the CAS/SAFEA International Partnership Program for Creative Research Teams. G.Y. W thanks the National Nature Science Foundation (grant No. 51401083). |
| Department | LNM冲击动力学与新型材料力学性能 |
| Classification | 一类 |
| Ranking | False |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://dspace.imech.ac.cn/handle/311007/59507 |
| Collection | 非线性力学国家重点实验室 |
| Corresponding Author | Zhang, TY (reprint author), Shanghai Univ, Mat Genome Inst, 99 Shangda Rd, Shanghai 200444, Peoples R China. |
| Recommended Citation GB/T 7714 | Yang XS,Wang YJ,Wang GY,et al. Time, stress, and temperature-dependent deformation in nanostructured copper: Stress relaxation tests and simulations[J]. ACTA MATERIALIA,2016,108:252-263. |
| APA | Yang XS.,Wang YJ.,Wang GY.,Zhai HR.,Dai LH.,...&Zhang, TY .(2016).Time, stress, and temperature-dependent deformation in nanostructured copper: Stress relaxation tests and simulations.ACTA MATERIALIA,108,252-263. |
| MLA | Yang XS,et al."Time, stress, and temperature-dependent deformation in nanostructured copper: Stress relaxation tests and simulations".ACTA MATERIALIA 108(2016):252-263. |
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| a2016-004.pdf（4249KB） | 期刊论文 | 出版稿 | 开放获取 | CC BY-NC-SA | View Download | |
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