Crack propagation mechanism of γ-TiAl alloy with pre-existing twin boundary

doi:10.1007/s11431-017-9307-5

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	Crack propagation mechanism of γ-TiAl alloy with pre-existing twin boundary
	Cao, Hui 1,2,3; Rui, ZhiYuan 1,2,3; Chen, WenKe 1,2,3; Feng, RuiCheng 1,2,3; Yan, ChangFeng 1,2,3
刊名	Science China Technological Sciences
	2019-09-01
卷号	62 期号:9 页码:1605-1615
关键词	Crack propagation Ductility Fracture toughness Microstructure Molecular dynamics Reaction kinetics Strain hardening Stress-strain curves Titanium alloys Yield stress Deformation and failure mechanism Deformation mechanism Ductile brittle transition Micro-structure evolutions Molecular dynamics simulations Plastic deformation mechanisms Propagation mechanism Twin boundaries
ISSN号	16747321
DOI	10.1007/s11431-017-9307-5
英文摘要	The deformation and failure mechanisms of γ-TiAl alloy with pre-existing crack and twin boundary are investigated by using molecular dynamics simulation. The effects of the crack position on the deformation and failure mechanisms of γ-TiAl specimen are analysed through the snapshots of crack propagation, microstructure of crack tip and stress-strain curves. The simulation results show that the dislocation motion is impeded, the good ductility can be maintained and the strength would be improved simultaneously by the twin boundary. The microstructure evolution of crack tip would change with crack positions. Essentially, the deformation behaviour mainly results from the reaction of dislocation-dislocation, dislocation-twin and twin-twin. Besides, the hierarchical twin is a main plastic deformation mechanism leading to strength of γ-TiAl specimen enhancement with non-compromising ductility and strain hardening. Based on stress-strain curves, it can be concluded that the yield strength varies with crack positions. They are the determinant factors for variation of the yield strength with different crack positions such as dislocation behaviour, stacking fault and hierarchical twin. The ductile-brittle transition associated with the dislocation motion and the decohesion failure of crack tip atom can be observed from the lower boundary crack and the center crack models. The crack propagation caused by the coalescent of the void and the crack tip is the main failure mechanism of γ-TiAl specimen. In addition, the results reveal that the mechanism of crack propagation would be influenced by pre-existing twin boundary which can prevent the crack propagation and improve the fracture toughness. © 2019, Science China Press and Springer-Verlag GmbH Germany, part of Springer Nature.
WOS研究方向	Engineering ; Materials Science
语种	英语
出版者	Springer Verlag
WOS记录号	WOS:000484901200013
内容类型	期刊论文
源URL	[http://ir.lut.edu.cn/handle/2XXMBERH/113940]
专题	机电工程学院兰州理工大学土木工程学院
作者单位	1.Engineering Research Center of Nonferrous Metallurgy’s New Equipment, Ministry of Education, Lanzhou University of Technology, Lanzhou; 730050, China; 2.School of Mechanical and Electronical Engineering, Lanzhou University of Technology, Lanzhou; 730050, China; 3.State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou; 730050, China
推荐引用方式 GB/T 7714	Cao, Hui,Rui, ZhiYuan,Chen, WenKe,et al. Crack propagation mechanism of γ-TiAl alloy with pre-existing twin boundary[J]. Science China Technological Sciences,2019,62(9):1605-1615.
APA	Cao, Hui,Rui, ZhiYuan,Chen, WenKe,Feng, RuiCheng,&Yan, ChangFeng.(2019).Crack propagation mechanism of γ-TiAl alloy with pre-existing twin boundary.Science China Technological Sciences,62(9),1605-1615.
MLA	Cao, Hui,et al."Crack propagation mechanism of γ-TiAl alloy with pre-existing twin boundary".Science China Technological Sciences 62.9(2019):1605-1615.