微结构和应力比对Ti-6A1-4V高周和超高周疲劳行为的影响

CORC > 力学研究所 > 中国科学院力学研究所 > 非线性力学国家重点实验室

	微结构和应力比对Ti-6A1-4V高周和超高周疲劳行为的影响
	刘小龙; 孙成奇; 周砚田; 洪友士; Hong, YS
刊名	金属学报
	2016
通讯作者邮箱	hongys@imech.ac.cn
卷号	52 期号:8 页码:923-930
关键词	Ti-6A1-4V alloy very-high-cycle fatigue microstructure stress ratio slip mechanism cleavage mechanism
ISSN号	0412-1961
其他题名	EFFECTS OF MICROSTRUCTURE AND STRESS RATIO ON HIGH-CYCLE AND VERY-HIGH-CYCLE FATIGUE BEHAVIOR OF Ti-6A1-4V ALLOY
产权排序	刘小龙, 中国科学院力学研究所, 非线性力学国家重点实验室, 北京 100190, 中国.; 孙成奇, 中国科学院力学研究所, 非线性力学国家重点实验室, 北京 100190, 中国.; 洪友士, 中国科学院力学研究所, 非线性力学国家重点实验室, 北京 100190, 中国.; 周砚田, 瓦房店轴承股份有限公司热处理分厂, 大连, 辽宁 116300, 中国.
中文摘要	采用旋转弯曲和超声疲劳实验分别测试了全等轴和等轴双态组织Ti-6A1-4V合金的高周和超高周疲劳性能,并用SEM观察了疲劳断口特征.结果表明:2种组织T1-6A1-4V合金的高周和超高周疲劳行为相似,不同应力比下,其S-N曲线均表现出单线形或双线形的形式;存在滑移机制和解理机制2种疲劳破坏机制.随应力比增加,2种组织Ti-6A1-4V合金的高周和超高周疲劳破坏机制均从滑移机制向解理机制转变.基于疲劳寿命和疲劳强度建立模型分析了应力比对2种机制之间竞争行为的影响,模型预测结果与实验结果趋势吻合.
英文摘要	Titanium alloys have been widely used as superior engineering materials because of their high specific strength, high temperature resistance and high corrosion resistance. In their engineering applications such as used in aircraft engines, titanium alloys may experience even 10~(10) fatigue cycles. Recently, faceted crack initiation was observed in high-cycle fatigue (HCF) and very-high-cycle fatigue (VHCF) regimes of titanium alloys, which resulted in a sharp decrease in fatigue strength. Therefore, the HCF and VHCF of titanium alloys have both scientific significance and engineering requirement. In this work, the effects of microstructure and stress ratio (R) on HCF and VHCF of a Ti-6A1-4V alloy have been investigated. Fatigue tests were conducted on a rotating-bending fatigue machine and an ultrasonic fatigue machine. All the fatigue fracture surfaces were observed by SEM. The results show that the HCF and VHCF behaviors of the fully-equiaxed and the bimodal Ti-6A1-4V alloy are similar. The observations of fracture surface indicate that two crack initiation mechanisms prevail, i.e. slip mechanism and cleavage mechanism. With the increase of stress ratio, the crack initiation mechanism switches from slip to cleavage. The S-N curves present the single-line type or the bilinear type. For the cases of rotating-bending and ultrasonic axial cycling with R= -1.0, -0.5 and 0.5, the S-N curves are single-line type corresponding to the slip mechanism or cleavage mechanism. For the cases of R= -0.1 and 0.1,the S-N curves are bilinear type corresponding to both slip and cleavage mechanisms. A model based on fatigue life and fatigue limit is proposed to describe the competition between the two mechanisms, which is in agreement with the experimental results.
关键词[WOS]	Ti-6A1-4V alloy ; very-high-cycle fatigue ; microstructure ; stress ratio ; slip mechanism ; cleavage mechanism
收录类别	CSCD
语种	中文
CSCD记录号	CSCD:5761349
内容类型	期刊论文
源URL	[http://dspace.imech.ac.cn/handle/311007/59798]
专题	力学研究所_非线性力学国家重点实验室
通讯作者	Hong, YS
推荐引用方式 GB/T 7714	刘小龙,孙成奇,周砚田,等. 微结构和应力比对Ti-6A1-4V高周和超高周疲劳行为的影响[J]. 金属学报,2016,52(8):923-930.
APA	刘小龙,孙成奇,周砚田,洪友士,&Hong, YS.(2016).微结构和应力比对Ti-6A1-4V高周和超高周疲劳行为的影响.金属学报,52(8),923-930.
MLA	刘小龙,et al."微结构和应力比对Ti-6A1-4V高周和超高周疲劳行为的影响".金属学报 52.8(2016):923-930.