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

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	Strength, strain-rate sensitivity and ductility of copper with nanoscale twins
	M. Dao ; L. Lu ; Y. F. Shen ; S. Suresh
刊名	Acta Materialia
	2006
卷号	54 期号:20 页码:5421-5432
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
ISSN号	1359-6454
中文摘要	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.
原文出处	://WOS:000242779300010
公开日期	2012-04-13
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/34169]
专题	金属研究所_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.