Strain localization and fatigue cracking behaviors of Cu bicrystal with an inclined twin boundary

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	Strain localization and fatigue cracking behaviors of Cu bicrystal with an inclined twin boundary
	L. L. Li; P. Zhang; Z. J. Zhang; H. F. Zhou; S. X. Qu; J. B. Yang; Z. F. Zhang
	2014
发表期刊	Acta Materialia
ISSN	1359-6454
卷号	73 页码:167-176
摘要	A Cu bicrystal with a twin boundary (TB) inclined at 45 degrees to the loading direction and its component monocrystal were specially designed to reveal their fatigue cracking mechanisms. Experimental results show that slip bands (SBs) parallel to the TB plane operated easily in both component grains and concentrated at the TB, while the SBs distributed more homogeneously in the monocrystal. It was revealed by atomistic modeling simulations and anisotropic elasticity theory that the screw dislocations transmitted to the TB could dissociate into two far-separated partial dislocations. Therefore, these dislocations would be confined in the TB with a high difficulty of cross-slip, leading to strain localization near the TB. With cyclic deformation, the fatigue crack nucleated along the TB preferentially in the bicrystal with fewer cycles than that for the SB crack in the monocrystal. Besides, unlike the impingement fatigue crack along high-angle grain boundaries with dislocation impingement, the shear fatigue crack initiates along the TB devoid of dislocation pile-ups. The existence of the TB inclined at 45 degrees to the loading direction induces strain localization and early intergranular fatigue cracking in the Cu bicrystal. These results could not only expand our knowledge of fatigue cracking mechanisms by clarifying how the boundary behaves without the piling up of dislocations, but also provide important implications for future interfacial optimization of materials. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
部门归属	[li, l. l. ; zhang, p. ; zhang, z. j. ; yang, j. b. ; zhang, z. f.] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. [zhou, h. f. ; qu, s. x.] zhejiang univ, dept engn mech, hangzhou 310027, zhejiang, peoples r china. ; zhang, zf (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, 72 wenhua rd, shenyang 110016, peoples r china. ; zhfzhang@imr.ac.cn
关键词	Cu Bicrystal Twin Boundary Slip Band Fatigue Crack Molecular Statics Coaxial Copper Bicrystals High-cycle Fatigue Grain-boundaries Crystallographic Orientation Deformation Mechanisms Screw Dislocations Ultrahigh-strength Maximum Strength Single-crystals Fcc Materials
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语种	英语
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/73274
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	L. L. Li,P. Zhang,Z. J. Zhang,et al. Strain localization and fatigue cracking behaviors of Cu bicrystal with an inclined twin boundary[J]. Acta Materialia,2014,73:167-176.
APA	L. L. Li.,P. Zhang.,Z. J. Zhang.,H. F. Zhou.,S. X. Qu.,...&Z. F. Zhang.(2014).Strain localization and fatigue cracking behaviors of Cu bicrystal with an inclined twin boundary.Acta Materialia,73,167-176.
MLA	L. L. Li,et al."Strain localization and fatigue cracking behaviors of Cu bicrystal with an inclined twin boundary".Acta Materialia 73(2014):167-176.