Time, stress, and temperature-dependent deformation in nanostructured copper: Stress relaxation tests and simulations

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	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
刊名	ACTA MATERIALIA
	2016
通讯作者邮箱	zhangty@shu.edu.cn
卷号	108 页码:252-263
关键词	Stress relaxation Nanotwin Copper HRTEM Atomistic simulations
ISSN号	1359-6454
通讯作者	Zhang, TY (reprint author), Shanghai Univ, Mat Genome Inst, 99 Shangda Rd, Shanghai 200444, Peoples R China.
产权排序	[Yang, Xu-Sheng; Zhai, Hui-Ru] Hong Kong Univ Sci & Technol, Dept Mech & Aerosp Engn, Kowloon, Hong Kong, Peoples R China; [Wang, Yun-Jiang; Dai, L. H.] Chinese Acad Sci, Inst Mech, State Key Lab Nonlinear Mech, Beijing 100190, Peoples R China; [Wang, Guo-Yong] Jilin Univ, Key Lab Automobile Mat, Dept Mat Sci & Engn, 5988 Renmin St, Changchun 130025, Peoples R China; [Zhang, Tong-Yi] Shanghai Univ, Mat Genome Inst, 99 Shangda Rd, Shanghai 200444, Peoples R China; [Zhang, Tong-Yi] Shanghai Univ, Shanghai Mat Genome Inst, 99 Shangda Rd, Shanghai 200444, Peoples R China
中文摘要	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.
分类号	一类
类目[WOS]	Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
研究领域[WOS]	Materials Science ; Metallurgy & Metallurgical Engineering
关键词[WOS]	Stress relaxation ; Nanotwin ; Copper ; HRTEM ; Atomistic simulations
收录类别	SCI ; EI
原文出处	http://dx.doi.org/10.1016/j.actamat.2016.02.021
语种	英语
WOS记录号	WOS:000374072700024
内容类型	期刊论文
源URL	[http://dspace.imech.ac.cn/handle/311007/59507]
专题	力学研究所_非线性力学国家重点实验室
推荐引用方式 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.