Unified factor controlling the dislocation evolution of fatigued face-centered cubic crystals

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	Unified factor controlling the dislocation evolution of fatigued face-centered cubic crystals
	Li, P.; Li, S. X.; Wang, Z. G.; Zhang, Z. F.; Li, P; Zhang, ZF (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China.
	2017-05-01
发表期刊	ACTA MATERIALIA
ISSN	1359-6454
卷号	129 页码:98-111
摘要	By analyzing the formation mechanisms of different types of dislocation patterns, one unified factor is developed to account for effects of slip mode and further explore the basic law of dislocation evolution in fatigued face-centered cubic (fcc) crystals. First of all, in the formation of persistent slip band (PSB) ladders, geometrically necessary dislocations (GNDs) accommodate the elastic/plastic strain gradients between the hard walls and soft channels and provide the long-range internal stresses required for the simultaneous compatible deformation of soft and hard regions. In typical wavy-slip materials, advanced dislocation patterns include the wall, cell and labyrinth structures. The formation of deformation band (DB) walls may be derived from the accumulation of GNDs. The appearance of labyrinth and cell structures should be related to the activation of critical and coplanar secondary slip systems, respectively. In typical planar-slip materials, the dislocation structures consist of the dipole arrays and stacking fault (SF) bands. The constant compression of the split distance between partials will lead to the conversion of the closely spaced dipole array to the SF bands, which indicates that both wavy-slip and planar-slip materials follow one unified evolution factor. This factor, labelled a in this work, may be described as the ratio of the annihilation distance of screw dislocations to the split distance between partials, which can characterize the slip mode. The higher the a value is, the easier will be the appearance of PSBs and various advanced dislocation patterns. With decreasing the a value, dislocation evolution gradually changes from 3D patterns to 2D structures. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.; By analyzing the formation mechanisms of different types of dislocation patterns, one unified factor is developed to account for effects of slip mode and further explore the basic law of dislocation evolution in fatigued face-centered cubic (fcc) crystals. First of all, in the formation of persistent slip band (PSB) ladders, geometrically necessary dislocations (GNDs) accommodate the elastic/plastic strain gradients between the hard walls and soft channels and provide the long-range internal stresses required for the simultaneous compatible deformation of soft and hard regions. In typical wavy-slip materials, advanced dislocation patterns include the wall, cell and labyrinth structures. The formation of deformation band (DB) walls may be derived from the accumulation of GNDs. The appearance of labyrinth and cell structures should be related to the activation of critical and coplanar secondary slip systems, respectively. In typical planar-slip materials, the dislocation structures consist of the dipole arrays and stacking fault (SF) bands. The constant compression of the split distance between partials will lead to the conversion of the closely spaced dipole array to the SF bands, which indicates that both wavy-slip and planar-slip materials follow one unified evolution factor. This factor, labelled a in this work, may be described as the ratio of the annihilation distance of screw dislocations to the split distance between partials, which can characterize the slip mode. The higher the a value is, the easier will be the appearance of PSBs and various advanced dislocation patterns. With decreasing the a value, dislocation evolution gradually changes from 3D patterns to 2D structures. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
部门归属	[li, p. ; li, s. x. ; wang, z. g. ; zhang, z. f.] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china ; [li, p.] ruhr univ bochum, inst werkstoffe, d-44780 bochum, germany
关键词	Fcc Crystals Dislocation Patterns Geometrically Necessary Dislocations Slip Mode Unified Evolution Factor
学科领域	Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
资助者	Alexander von Humboldt Foundation; National Natural Science Foundation of China [51001104, 51331007]; Special Funding for the Youth Innovation Promotion Association by Chinese Academy of Sciences
收录类别	SCI
语种	英语
WOS记录号	WOS:000400033900011
引用统计	被引频次：77[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/321006/78166
专题	中国科学院金属研究所
通讯作者	Li, P; Zhang, ZF (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China.
推荐引用方式 GB/T 7714	Li, P.,Li, S. X.,Wang, Z. G.,et al. Unified factor controlling the dislocation evolution of fatigued face-centered cubic crystals[J]. ACTA MATERIALIA,2017,129:98-111.
APA	Li, P.,Li, S. X.,Wang, Z. G.,Zhang, Z. F.,Li, P,&Zhang, ZF .(2017).Unified factor controlling the dislocation evolution of fatigued face-centered cubic crystals.ACTA MATERIALIA,129,98-111.
MLA	Li, P.,et al."Unified factor controlling the dislocation evolution of fatigued face-centered cubic crystals".ACTA MATERIALIA 129(2017):98-111.