Study on notch fracture of TiAl alloys at room temperature

doi:10.1007/s11661-004-0355-6

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	Study on notch fracture of TiAl alloys at room temperature
	Chen, JH ; Cao, R ; Wang, GZ ; Zhang, J
刊名	METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
	2004-02
卷号	35A 期号:2 页码:439-456
关键词	Crack initiation Crack propagation Delamination Finite element method Fracture Interfaces (materials) Nucleation Numerical analysis Plastic deformation Polycrystalline materials Temperature Tensile stress Lamellar interfaces Notch fracture Titanium aluminum alloys
ISSN号	1073-5623
DOI	10.1007/s11661-004-0355-6
英文摘要	In-situ observations of fracture processes combined with one-to-one observations of fracture surfaces and finite-element method (FEM) calculations are carried out on notched tensile specimens of two-phase polycrystalline TiAl alloys. The results reveal that most cracks are initiated and propagated along the interfaces between lamellae before plastic deformation. The driving force for the fracture process is the tensile stress, which is consistent with a previous study.([1]) in specimens with a slit notch, most cracks are initiated directly from the notch root and extended along lamellar interfaces. The main crack can be stopped or deflected into a delamination mode by a barrier grain with a lamellar interface orientation deviated from the direction of crack propagation. In this case, new cracks are nucleated along lamellar interfaces of grains with favorable orientation ahead of the barrier grain. The main crack and a new crack are then linked by the translamellar cleavage fracture of the barrier grain with increasing applied load. In order to extend the main crack, further increases of the applied load are needed to move the high stress region into the ligament until catastrophic fracture. The FEM calculations reveal that the strength along lamellar interfaces (interlamellar fracture) is as low as 50 MPa and appreciably lower than the strength perpendicular to the lamellae (translamellar fracture), which shows a value higher than 120 MPa. This explains the reason why cracks nucleate and preferably extend along the lamellar interfaces.
WOS研究方向	Materials Science ; Metallurgy & Metallurgical Engineering
语种	英语
出版者	MINERALS METALS MATERIALS SOC
WOS记录号	WOS:000188840600005
状态	已发表
内容类型	期刊论文
源URL	[http://119.78.100.223/handle/2XXMBERH/35862]
专题	兰州理工大学
通讯作者	Chen, JH
作者单位	1.Lanzhou Univ Sci & Technol, Ganzui Univ Technol, State Key Lab New Nonferrous Mat, Lanzhou 730050, Peoples R China 2.Cent Iron & Steel Res Inst, High Temp Mat Res Div, Beijing 100081, Peoples R China
推荐引用方式 GB/T 7714	Chen, JH,Cao, R,Wang, GZ,et al. Study on notch fracture of TiAl alloys at room temperature[J]. METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE,2004,35A(2):439-456.
APA	Chen, JH,Cao, R,Wang, GZ,&Zhang, J.(2004).Study on notch fracture of TiAl alloys at room temperature.METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE,35A(2),439-456.
MLA	Chen, JH,et al."Study on notch fracture of TiAl alloys at room temperature".METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE 35A.2(2004):439-456.