The micro-mechanism of fatigue crack propagation for a forged Mg-Zn-Y-Zr alloy in the gigacycle fatigue regime

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	The micro-mechanism of fatigue crack propagation for a forged Mg-Zn-Y-Zr alloy in the gigacycle fatigue regime
	D. K. Xu; L. Liu; Y. B. Xu; E. H. Han
	2008
发表期刊	Journal of Alloys and Compounds
ISSN	0925-8388
卷号	454 期号:1-2 页码:123-128
摘要	In the gigacycle fatigue regime (106 to 109 Cycles), the micro-mechanism of fatigue crack propagation for a forged Mg-Zn-Y-Zr alloy subjected to temper treatment (T5) has been studied. High-magnified images of the different crack propagation regions indicate that when the effective stress intensity factor K(eff) is below 3.2 MPa m(1/2), in Region 1, the fracture surface is smooth covered with many flat facets. However, when the stress intensity factor is higher than 3.2 MPa m(1/2), in Region 2, many larnellar semi-cleavage planes caused by rod-like beta(1)', precipitates can be observed, resulting in a rather rough fracture surface. However, in Region 3, no lamellar semi-cleavage planes but lots of zonal distributed Mg(3)Zn(3)Y(2) phases can be observed. It suggests that with the increase of the crack-tip driving force, the preferential path for fatigue crack propagation changes from the rod-like beta(1)' precipitates to the zonal distributed Mg(3)Zn(3)Y(2) phases. In addition, two kinds of fatigue striations, i.e. striations formed on the flat fracture surface and striations formed on the cleavage steps, have been observed. Based on double-slip and plastic obtuseness at the crack tip, the forming mechanism of the fatigue striations on the cleavage steps has been discussed. (C) 2006 Elsevier B.V. All rights reserved.
部门归属	[xu, d. k.; han, e. h.] chinese acad sci, met res inst, environm corros ctr, shenyang 110016, peoples r china. [xu, d. k.; liu, l.; xu, y. b.] chinese acad sci, met res inst, shenyang natl lab mat sci, shenyang 110016, peoples r china.;xu, dk (reprint author), chinese acad sci, met res inst, environm corros ctr, shenyang 110016, peoples r china;dkxu@imr.ac.cn
关键词	M-zn-y-zr Magnesium Alloy Gigacycle Fatigue Micro-mechanism Magnesium Alloy Re Alloys Mechanical-properties Cycle Fatigue Life Regime Behavior Steels
URL	查看原文
WOS记录号	WOS:000255215000025
引用统计	被引频次：14[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/321006/33242
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	D. K. Xu,L. Liu,Y. B. Xu,et al. The micro-mechanism of fatigue crack propagation for a forged Mg-Zn-Y-Zr alloy in the gigacycle fatigue regime[J]. Journal of Alloys and Compounds,2008,454(1-2):123-128.
APA	D. K. Xu,L. Liu,Y. B. Xu,&E. H. Han.(2008).The micro-mechanism of fatigue crack propagation for a forged Mg-Zn-Y-Zr alloy in the gigacycle fatigue regime.Journal of Alloys and Compounds,454(1-2),123-128.
MLA	D. K. Xu,et al."The micro-mechanism of fatigue crack propagation for a forged Mg-Zn-Y-Zr alloy in the gigacycle fatigue regime".Journal of Alloys and Compounds 454.1-2(2008):123-128.