Strength, strain-rate sensitivity and ductility of copper with nanoscale twins

IMR OpenIR

	Strength, strain-rate sensitivity and ductility of copper with nanoscale twins
	M. Dao; L. Lu; Y. F. Shen; S. Suresh
	2006
发表期刊	Acta Materialia
ISSN	1359-6454
卷号	54 期号:20 页码:5421-5432
摘要	We present a comprehensive computational analysis of the deformation of ultrafine crystalline pure Cu with nanoscale growth twins. This physically motivated model benefits from our experimental studies of the effects of the density of coherent nanotwins on the plastic deformation characteristics of Cu, and from post-deformation transmission electron microscopy investigations of dislocation structures in the twinned metal. The analysis accounts for high plastic anisotropy and rate sensitivity anisotropy by treating the twin boundary as an internal interface and allowing special slip geometry arrangements that involve soft and hard modes of deformation. This model correctly predicts the experimentally observed trends of the effects of twin density on flow strength, rate sensitivity of plastic flow and ductility, in addition to matching many of the quantitative details of plastic deformation reasonably well. The computational simulations also provide critical mechanistic insights into why the metal with nanoscale twins can provide the same level of yield strength, hardness and strain rate sensitivity as a nanostructured counterpart without twins (but of grain size comparable to the twin spacing of the twinned Cu). The analysis also offers some useful understanding of why the nanotwinned Qu with high strength does not lead to diminished ductility with structural refinement involving twins, whereas nanostructured Cu normally causes the ductility to be compromised at the expense of strength upon grain refinement. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
部门归属	mit, dept mat sci & engn, cambridge, ma 02139 usa. chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china.;suresh, s (reprint author), mit, dept mat sci & engn, 77 massachusetts ave,room 40140, cambridge, ma 02139 usa;ssuresh@mit.edu
关键词	Nanocrystalline Materials Nanoscale Twins Crystal Plasticity Copper Computational Model Ni Multilayer System Single-crystals Nanocrystalline Metals Localized Deformation Plastic-deformation Activation Volume Cu Microstructures Simulations Patterns
URL	查看原文
WOS记录号	WOS:000242779300010
引用统计	被引频次：478[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/34169
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	M. Dao,L. Lu,Y. F. Shen,et al. Strength, strain-rate sensitivity and ductility of copper with nanoscale twins[J]. Acta Materialia,2006,54(20):5421-5432.
APA	M. Dao,L. Lu,Y. F. Shen,&S. Suresh.(2006).Strength, strain-rate sensitivity and ductility of copper with nanoscale twins.Acta Materialia,54(20),5421-5432.
MLA	M. Dao,et al."Strength, strain-rate sensitivity and ductility of copper with nanoscale twins".Acta Materialia 54.20(2006):5421-5432.