Strong trapping and slow diffusion of helium in a tungsten grain boundary

IMR OpenIR

	Strong trapping and slow diffusion of helium in a tungsten grain boundary
	Wang, Xin-Xin; Niu, Liang-Liang; Wang, Shaoqing; Niu, LL (reprint author), Beihang Univ, Dept Phys, Beijing 100191, Peoples R China.
	2017-04-01
发表期刊	JOURNAL OF NUCLEAR MATERIALS
ISSN	0022-3115
卷号	487 页码:158-166
摘要	We have investigated the segregation, trapping and diffusion of He in a Sigma 3 < 110 >{111} W grain boundary (GB) using combined techniques of ab initio and classical atomistic simulations. We show that, with an average segregation energy of -3.20 eV, the strong He trapping can be attributed to a GB interstitial trapping or a vacancy trapping mechanism, while an average energy barrier of 1.97 eV leads to a slow diffusion of He in the GB plane. We further reveal by molecular dynamics simulations that the He diffusion will be dictated by GB migration through the motion of GB disconnections. Interestingly, we also observe a He-induced GB structural transition in classical simulations. The present work suggests that the GB does not provide fast transport channel for He, providing useful reference for the possible application of polycrystalline W under He irradiation in advanced nuclear fusion reactors. (C) 2017 Elsevier B.V. All rights reserved.; We have investigated the segregation, trapping and diffusion of He in a Sigma 3 < 110 >{111} W grain boundary (GB) using combined techniques of ab initio and classical atomistic simulations. We show that, with an average segregation energy of -3.20 eV, the strong He trapping can be attributed to a GB interstitial trapping or a vacancy trapping mechanism, while an average energy barrier of 1.97 eV leads to a slow diffusion of He in the GB plane. We further reveal by molecular dynamics simulations that the He diffusion will be dictated by GB migration through the motion of GB disconnections. Interestingly, we also observe a He-induced GB structural transition in classical simulations. The present work suggests that the GB does not provide fast transport channel for He, providing useful reference for the possible application of polycrystalline W under He irradiation in advanced nuclear fusion reactors. (C) 2017 Elsevier B.V. All rights reserved.
部门归属	[wang, xin-xin ; wang, shaoqing] chinese acad sci, shenyang natl lab mat sci, inst met res, shenyang 110016, peoples r china ; [wang, xin-xin] univ sci & technol china, sch mat sci & engn, hefei 230026, peoples r china ; [niu, liang-liang] beihang univ, dept phys, beijing 100191, peoples r china ; [niu, liang-liang] univ michigan, dept nucl engn & radiol sci, ann arbor, mi 48109 usa
关键词	Grain Boundary Helium Segregation Diffusion Tungsten
学科领域	Materials Science, Multidisciplinary ; Nuclear Science & Technology
资助者	National Major Research Program of China [2016YFB0701302]; Informalization Construction Project of Chinese Academy of Sciences during the 11th Five Year Plan Period [INFO-115-b01]; Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund (the second phase)
收录类别	SCI
语种	英语
WOS记录号	WOS:000399506900019
引用统计	被引频次：42[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/321006/78206
专题	中国科学院金属研究所
通讯作者	Niu, LL (reprint author), Beihang Univ, Dept Phys, Beijing 100191, Peoples R China.
推荐引用方式 GB/T 7714	Wang, Xin-Xin,Niu, Liang-Liang,Wang, Shaoqing,et al. Strong trapping and slow diffusion of helium in a tungsten grain boundary[J]. JOURNAL OF NUCLEAR MATERIALS,2017,487:158-166.
APA	Wang, Xin-Xin,Niu, Liang-Liang,Wang, Shaoqing,&Niu, LL .(2017).Strong trapping and slow diffusion of helium in a tungsten grain boundary.JOURNAL OF NUCLEAR MATERIALS,487,158-166.
MLA	Wang, Xin-Xin,et al."Strong trapping and slow diffusion of helium in a tungsten grain boundary".JOURNAL OF NUCLEAR MATERIALS 487(2017):158-166.