Improved fatigue properties of ultrafine-grained copper under cyclic torsion loading

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	Improved fatigue properties of ultrafine-grained copper under cyclic torsion loading
	R. H. Li; Z. J. Zhang; P. Zhang; Z. F. Zhang
	2013
发表期刊	Acta Materialia
ISSN	1359-6454
卷号	61 期号:15 页码:5857-5868
摘要	In this study, fatigue behaviors of pure copper with different grain sizes are investigated under cyclic tension-compression and torsion loadings. The fatigue responses of ultrafine-grained (UFG) Cu subjected to equal-channel angular pressing (ECAP) are compared and contrasted with those of coarse-grained (CG) and cold-rolled (CR) Cu. It is found from the S-N curves under the two different loading modes that, in the high-cycle fatigue (HCF) range, the fatigue strength of Cu does not exhibit strong dependence on the grain size under cyclic tension-compression loading, whereas the fatigue strength of UFG Cu is greatly improved over those of CG and CR Cu under cyclic torsion loading. Under cyclic tension-compression loading, the fatigue strength exponent decreases with the refinement of grain size; however, under cyclic torsion loading, with decreasing grain size, its fatigue strength exponent shows the opposite trend and goes up. To explain the phenomena above, the relations between the fatigue strength exponent and fatigue strength coefficient are discussed. Based on the two main stages of fatigue failure (crack initiation and propagation stages), the influences of grain size on fatigue strength exponent and fatigue strength in the HCF range under the two fatigue modes are comprehensively analyzed. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
部门归属	[li, r. h. ; zhang, z. j. ; zhang, p. ; zhang, z. f.] chinese acad sci, shenyang natl lab mat sci, inst met res, shenyang 110016, peoples r china. ; zhang, zf (reprint author), chinese acad sci, shenyang natl lab mat sci, inst met res, shenyang 110016, peoples r china. ; zhfzhang@imr.ac.cn
关键词	Ultrafine-grained Copper Equal-channel Angular Pressing Cyclic Torsion Loading Fatigue Strength Fatigue Crack Severe Plastic-deformation High-pressure Torsion Mode-iii Loadings Mechanical-properties Crack-growth Shear Bands Strength Behavior Alloy Cu
URL	查看原文
语种	英语
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/71325
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	R. H. Li,Z. J. Zhang,P. Zhang,et al. Improved fatigue properties of ultrafine-grained copper under cyclic torsion loading[J]. Acta Materialia,2013,61(15):5857-5868.
APA	R. H. Li,Z. J. Zhang,P. Zhang,&Z. F. Zhang.(2013).Improved fatigue properties of ultrafine-grained copper under cyclic torsion loading.Acta Materialia,61(15),5857-5868.
MLA	R. H. Li,et al."Improved fatigue properties of ultrafine-grained copper under cyclic torsion loading".Acta Materialia 61.15(2013):5857-5868.