Molecular Dynamics Simulation of Nano Single Crystal Gamma-TiAl Alloy Strain Rate Effect

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	Molecular Dynamics Simulation of Nano Single Crystal Gamma-TiAl Alloy Strain Rate Effect
	Luo Dechun 1; Zhang Ling 2; Fu Rong 1; Cao Hui 1; Rui Zhiyua 1
刊名	RARE METAL MATERIALS AND ENGINEERING
	2018-03
卷号	47 期号:3 页码:853-859
关键词	gamma-TiAl alloy strain rate molecular dynamics crack propagation
ISSN号	1002-185X
英文摘要	The propagation form of the preset edge crack in the nano single crystal gamma-TiAl at different strain rates were simulated by molecular dynamics. Dynamic uniaxial tension for preset edge cracks was carried out by velocity loading in the single crystal gamma-TiAl within 5.0 x 10(7) similar to 7.5 x 10(9) s(-1). The results show that the crack propagation form varies with the range of strain rate. In the non-sensitive region ((epsilon)over dot <= 4 x 10(8) s(-1)), the crack propagates in a brittle cleavage manner. In the sensitive region (4.0 x 10(8) s(-1) < (epsilon)over dot <= 1.0 x 10(9) s(-1)), it exhibits cleavage extension feature early; in the latter stage, the slip dislocation is emitted from the crack tip, and the void defect initiates the place where dislocation pile up and then grow to the child crack, the child crack links the main crack when it bias 45 degrees when (epsilon)over dot <= 5.0 x 10(8) s(-1), but it connects the main crack at the same direction under 5.0 x 10(8) s(-1) < (epsilon)over dot <= 1.0 x 10(9) s(-1), thus leading to the fracture finally. In the sharp-change region ((epsilon)over dot >= 1.0x10(9) s(-1)), the crack does not craze at the maximum stress for the reinforcement of strain, and the stress decreases after it continues to increase for some time. The non-crystallizing of the atom structure occurs near the crack tip because of high strain rate, and then the micro crack initiates in the area of structure disordered, the micro crack growth causes fracture of the "test specimen" eventually.
WOS研究方向	Materials Science ; Metallurgy & Metallurgical Engineering
语种	中文
出版者	NORTHWEST INST NONFERROUS METAL RESEARCH
WOS记录号	WOS:000429884900023
状态	已发表
内容类型	期刊论文
源URL	[http://119.78.100.223/handle/2XXMBERH/32760]
专题	机电工程学院土木工程学院
通讯作者	Luo Dechun
作者单位	1.Lanzhou Univ Technol, Key Lab Mfg Technol & Applicat, Minist Educ, Lanzhou 730050, Gansu, Peoples R China 2.Lanzhou Inst Technol, Lanzhou 730050, Gansu, Peoples R China
推荐引用方式 GB/T 7714	Luo Dechun,Zhang Ling,Fu Rong,et al. Molecular Dynamics Simulation of Nano Single Crystal Gamma-TiAl Alloy Strain Rate Effect[J]. RARE METAL MATERIALS AND ENGINEERING,2018,47(3):853-859.
APA	Luo Dechun,Zhang Ling,Fu Rong,Cao Hui,&Rui Zhiyua.(2018).Molecular Dynamics Simulation of Nano Single Crystal Gamma-TiAl Alloy Strain Rate Effect.RARE METAL MATERIALS AND ENGINEERING,47(3),853-859.
MLA	Luo Dechun,et al."Molecular Dynamics Simulation of Nano Single Crystal Gamma-TiAl Alloy Strain Rate Effect".RARE METAL MATERIALS AND ENGINEERING 47.3(2018):853-859.