Weak fatigue notch sensitivity in a biomedical titanium alloy exhibiting nonlinear elasticity

IMR OpenIR

	Weak fatigue notch sensitivity in a biomedical titanium alloy exhibiting nonlinear elasticity
	Zhang, JR; Shah, SAA; Hao, YL; Li, SJ; Yang, R; Hao, YL (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Liaoning, Peoples R China.
	2018-04-01
发表期刊	SCIENCE CHINA-MATERIALS
ISSN	2095-8226
卷号	61 期号:4 页码:537-544
摘要	It is well known that metallic materials exhibit worse fatigue damage tolerance as they behave stronger in strength and softer in modulus. This raises concern on the long term safety of the recently developed biomechanical compatible titanium alloys with high strength and low modulus. Here we demonstrate via a model alloy, Ti-24Nb-4Zr-8Sn in weight percent, that this group of multifunctional titanium alloys possessing nonlinear elastic deformation behavior is tolerant in fatigue notch damage. The results reveal that the alloy has a high strength-to-modulus (sigma/E) ratio reaching 2% but its fatigue notch sensitivity (q) is low, which decreases linearly from 0.45 to 0.25 as stress concentration factor increases from 2 to 4. This exceeds significantly the typical relationship between sigma/E and q of other metallic materials exhibiting linear elasticity. Furthermore, fatigue damage is characterized by an extremely deflected mountain-shape fracture surface, resulting in much longer and more tortuous crack growth path as compared to these linear elastic materials. The above phenomena can be explained by the nonlinear elasticity and its induced stress relief at the notch root in an adaptive manner of higher stress stronger relief. This finding provides a new strategy to balance high strength and good damage tolerance property of metallic materials.; It is well known that metallic materials exhibit worse fatigue damage tolerance as they behave stronger in strength and softer in modulus. This raises concern on the long term safety of the recently developed biomechanical compatible titanium alloys with high strength and low modulus. Here we demonstrate via a model alloy, Ti-24Nb-4Zr-8Sn in weight percent, that this group of multifunctional titanium alloys possessing nonlinear elastic deformation behavior is tolerant in fatigue notch damage. The results reveal that the alloy has a high strength-to-modulus (sigma/E) ratio reaching 2% but its fatigue notch sensitivity (q) is low, which decreases linearly from 0.45 to 0.25 as stress concentration factor increases from 2 to 4. This exceeds significantly the typical relationship between sigma/E and q of other metallic materials exhibiting linear elasticity. Furthermore, fatigue damage is characterized by an extremely deflected mountain-shape fracture surface, resulting in much longer and more tortuous crack growth path as compared to these linear elastic materials. The above phenomena can be explained by the nonlinear elasticity and its induced stress relief at the notch root in an adaptive manner of higher stress stronger relief. This finding provides a new strategy to balance high strength and good damage tolerance property of metallic materials.
部门归属	[zhang, jinrui ; shah, syed a. a. ; hao, yulin ; li, shujun ; yang, rui] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, liaoning, peoples r china ; [zhang, jinrui] univ sci & technol china, sch mat sci & engn, shenyang 110016, liaoning, peoples r china
关键词	High-cycle Fatigue Modulus Ti-24nb-4zr-8sn Alloy Plastic-deformation Crack Deflection Stainless-steel Carbon Steels Nano-scale Behavior Ti-6al-4v Microstructure
学科领域	Materials Science, Multidisciplinary
资助者	National Key Research and Development Program of China [2016YFC1102601, 2017YFC1104901]; National Natural Science Foundation of China [51571190, 51631007]; Key Research Program of Frontier Sciences of Chinese Academy of Sciences [QYZDJ-SSW-JSC031]
收录类别	SCI
语种	英语
WOS记录号	WOS:000432685300008
引用统计	被引频次：7[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/321006/79382
专题	中国科学院金属研究所
通讯作者	Hao, YL (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Liaoning, Peoples R China.
推荐引用方式 GB/T 7714	Zhang, JR,Shah, SAA,Hao, YL,et al. Weak fatigue notch sensitivity in a biomedical titanium alloy exhibiting nonlinear elasticity[J]. SCIENCE CHINA-MATERIALS,2018,61(4):537-544.
APA	Zhang, JR,Shah, SAA,Hao, YL,Li, SJ,Yang, R,&Hao, YL .(2018).Weak fatigue notch sensitivity in a biomedical titanium alloy exhibiting nonlinear elasticity.SCIENCE CHINA-MATERIALS,61(4),537-544.
MLA	Zhang, JR,et al."Weak fatigue notch sensitivity in a biomedical titanium alloy exhibiting nonlinear elasticity".SCIENCE CHINA-MATERIALS 61.4(2018):537-544.