Molecular Dynamics Simulation of Tensile Deformation and Fracture of gamma-TiAl with and without Surface Defects

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	Molecular Dynamics Simulation of Tensile Deformation and Fracture of gamma-TiAl with and without Surface Defects
	Wu, HN; Xu, DS; Wang, H; Yang, R; Xu, DS (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang 110016, Peoples R China.
	2016-10-01
发表期刊	JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
ISSN	1005-0302
卷号	32 期号:10 页码:1033-1042
摘要	Molecular dynamics simulation of uniaxial tension along [001] has been performed to study the influence of various surface defects on the initiation of plastic deformation and fracture of gamma-TiAl single crystals. The results indicate that brittle fracture occurs in perfect bulk; surfaces and edges will be detrimental to the strength of materials and provide dislocation nucleation site. The defects on surfaces and edges cause further weakening with various effects depending on defect type, size, position and orientation, while the edge dimples are the most influential. For gamma-TiAl rods with surface dimples, dislocations nucleate from an edge of the rod when dimples are small, dimple dislocation nucleation occurs only when the dimples are larger than a strain rate dependent critical size. The dislocations nucleated upon [001] tension are super dislocations with Burger vectors <011] or 1/2 < 112] containing four 1/6 < 112 > partials. The effects of surface scratches are orientation and shape sensitive. Scratches parallel to the loading direction have little influence, while sharp ones perpendicular to the loading direction may cause crack and thus should be avoided. This simulation also shows that, any type of surface defect would lower strength, and cause crack in some cases. But some may facilitate dislocation nucleation and improve ductility of TiAl if well controlled. Copyright (C) 2016, The editorial office of Journal of Materials Science & Technology. Published by Elsevier Limited.
部门归属	[wu, h. n. ; xu, d. s. ; wang, h. ; yang, r.] chinese acad sci, inst met res, shenyang 110016, peoples r china
关键词	Intermetallic Compounds Superdislocation Fracture Surface Defects Molecular Dynamics
学科领域	Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
资助者	National Basic Research Program of China [2011CB606404]; National Natural Science Foundation of China [51171195]; GM Research Project; CAS Shenyang Supercomputing Center
收录类别	sci
语种	英语
WOS记录号	WOS:000386246600008
引用统计	被引频次：50[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/321006/76246
专题	中国科学院金属研究所
通讯作者	Xu, DS (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang 110016, Peoples R China.
推荐引用方式 GB/T 7714	Wu, HN,Xu, DS,Wang, H,et al. Molecular Dynamics Simulation of Tensile Deformation and Fracture of gamma-TiAl with and without Surface Defects[J]. JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY,2016,32(10):1033-1042.
APA	Wu, HN,Xu, DS,Wang, H,Yang, R,&Xu, DS .(2016).Molecular Dynamics Simulation of Tensile Deformation and Fracture of gamma-TiAl with and without Surface Defects.JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY,32(10),1033-1042.
MLA	Wu, HN,et al."Molecular Dynamics Simulation of Tensile Deformation and Fracture of gamma-TiAl with and without Surface Defects".JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY 32.10(2016):1033-1042.