The behavior of crack initiation and early growth in high-cycle and very-high-cycle fatigue regimes for a titanium alloy

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	The behavior of crack initiation and early growth in high-cycle and very-high-cycle fatigue regimes for a titanium alloy
	Pan XN(潘向南); Su H(苏杭); Sun CQ(孙成奇); Hong YS(洪友士)
	2018-10-01
会议日期	APR 10-12, 2017
会议地点	Bonifacio, FRANCE
关键词	Very-high-cycle fatigue Crack initiation Mean stress Titanium alloy Equiaxed microstructure
页码	67-78
英文摘要	The behavior of crack initiation and early growth in high-cycle fatigue (HCF) and very-high-cycle fatigue (VHCF) regimes for a TC4 titanium alloy with equiaxed microstructure was investigated. Fatigue tests were conducted via ultrasonic axial cycling (20 kHz) superimposed by an amount of tensile load. The effect of tensile mean stress on fatigue endurance was plotted with a Haigh diagram formulated by Goodman, Gerber and the present formula. Fractography was observed by scanning electron microscopy, and three failure types of crack initiation were classified: surface-without-RA (rough area), surface-with-RA and interior-with-RA. Profile samples from the crack initiation region were prepared and examined by transmission electron microscopy with selected area electron diffraction. The observations show that a nanograin layer prevails underneath the fracture surface in the RA region only for the VHCF case with a stress ratio R = -1. The nanograin formation mechanism was explained by the numerous cyclic pressing (NCP) model.
会议录	INTERNATIONAL JOURNAL OF FATIGUE
资助机构	National Natural Science Foundation of China [11572325]; Strategic Priority Research Program of the Chinese Academy of Sciences [XDB22040503, XDB22020201]
语种	英语
WOS记录号	WOS:000449895700009
内容类型	会议论文
源URL	[http://dspace.imech.ac.cn/handle/311007/78556]
专题	力学研究所_非线性力学国家重点实验室
作者单位	Chinese Acad Sci, Inst Mech, State Key Lab Nonlinear Mech, Beijing 100190, Peoples R China、Univ Chinese Acad Sci, Sch Engn Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Pan XN,Su H,Sun CQ,et al. The behavior of crack initiation and early growth in high-cycle and very-high-cycle fatigue regimes for a titanium alloy[C]. 见:. Bonifacio, FRANCE. APR 10-12, 2017.