期刊
INTERNATIONAL JOURNAL OF FATIGUE
卷 115, 期 -, 页码 67-78出版社
ELSEVIER SCI LTD
DOI: 10.1016/j.ijfatigue.2018.03.021
关键词
Very-high-cycle fatigue; Crack initiation; Mean stress; Titanium alloy; Equiaxed microstructure
资金
- National Natural Science Foundation of China [11572325]
- Strategic Priority Research Program of the Chinese Academy of Sciences [XDB22040503, XDB22020201]
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.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据