Cyclic hardening mechanisms in 001 copper single crystals

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	Cyclic hardening mechanisms in 001 copper single crystals
	B. Gong; Z. R. Wang; Z. G. Wang
	1998
发表期刊	Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing
ISSN	0921-5093
卷号	245 期号:1 页码:55-63
摘要	Friction stress and back stress of [001] Cu single crystals during cyclic deformation were derived from cyclic stress-strain hysteresis loops by using the Cottrell method and the results are compared with those for single slip crystals. The cyclic hardening features of the [001] crystals are described in terms of the friction stress and back stress. Specific, detailed study was carried out on the sample cycled with a plastic strain amplitude of 1.8 x 10(-3). It has been shown that both the 'true' friction stress, i.e. the cyclic yield stress, and the back stress in the [001] crystals increase much more rapidly than those in single slip crystals in the hardening stage. In the saturation stage, however, only the friction stress in the [001] crystal is higher than its correspondent in the single slip crystals, while the back stresses in these two types of crystals are close to each other. The higher friction stress in the [001] crystal is related to the higher density of jogs produced by the dislocation reactions between the primary and critical slip systems, and the existence of secondary dislocations in channels. The higher back stress in the hardening stage is attributed to the higher dislocation density in loop patches introduced by dislocation reactions in the first dozen of cycles. By modifying the Kulhlmann-Wilsdorf and Laird model, it is possible now to express quantitatively both the back stress and the shear stress in a cyclically deformed crystal with a particular orientation as functions of the applied strain amplitude as well as an orientation-dependent factor: the hardening coefficient for the first stage of unidirectional deformation. The predictions from these expressions for multiple slip crystals are in very good agreement with experimental data. (C) 1998 Elsevier Science S.A. All rights reserved.
部门归属	univ toronto, dept met & mat sci, toronto, on m5s 3e4, canada. chinese acad sci, inst met res, state key lab fatigue & fracture mat, shenyang, peoples r china.;wang, zr (reprint author), univ toronto, dept met & mat sci, toronto, on m5s 3e4, canada
关键词	Friction Stress Back Stress Multiple Slip Crystals Kw-l Model Double Slip Deformation-behavior Stress
URL	查看原文
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/37664
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	B. Gong,Z. R. Wang,Z. G. Wang. Cyclic hardening mechanisms in 001 copper single crystals[J]. Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing,1998,245(1):55-63.
APA	B. Gong,Z. R. Wang,&Z. G. Wang.(1998).Cyclic hardening mechanisms in 001 copper single crystals.Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing,245(1),55-63.
MLA	B. Gong,et al."Cyclic hardening mechanisms in 001 copper single crystals".Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing 245.1(1998):55-63.