Formation of point defects in TiAl and NiAl

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	Formation of point defects in TiAl and NiAl
	Y. L. Hao; R. Yang; Y. Song; Y. Y. Cui; D. Li; A. Niinomi
	2004
发表期刊	Intermetallics
ISSN	0966-9795
卷号	12 期号:7-9 页码:951-956
摘要	A mean-field model is proposed to estimate the atom-atom and atom-vacancy bond energies of intermetallic compounds, with the results of first principles calculations as input. The variation of point defects with temperature and chemical composition estimated with the model agreed with experimental measurements for TiAl and NiAl alloys. In particular, off-stoichiometric effect considered in this treatment was found to increase vacancy concentration in Al-rich but decrease it in Ti-rich TiAl alloys. As a result, the differences in vacancy concentration between Al-rich and Al-lean TiAl alloys are larger than those reported in previous studies. For NiAl alloys, the consideration of off-stoichiometric influence yields lower vacancy concentration on the Al-rich side but higher concentration on the Ni-rich side. The present model suggests that constitutional vacancies are present, but anti-site defects are forbidden in Al-rich NiAl at 0 K. For concentrated Al-rich NiAl, the vacancy concentration has its maximum at 0 K, and gradually decreases with rising temperature until diffusion is activated. The reason why constitutional vacancies are more difficult to form at low temperatures in TiAl than in NiAl is discussed. (C) 2004 Elsevier Ltd. All rights reserved.
部门归属	chinese acad sci, inst met res, titanium alloy lab, shenyang 110016, peoples r china. univ london queen mary coll, dept mat, london e1 4ns, england. toyohashi univ technol, dept product syst engn, toyohashi, aichi 4418580, japan.;yang, r (reprint author), chinese acad sci, inst met res, titanium alloy lab, 72 wenhua rd, shenyang 110016, peoples r china;ryang@imr.ac.cn
关键词	Nickel Alummides Titanium Aluminides Based On Nial Based On Tial Defects : Point Defects Defects : Theory Intermetallic Compound Feal High-temperature Region Nickel-aluminum System Behavior Alloys Al Vacancies Energies
URL	查看原文
WOS记录号	WOS:000223396900038
引用统计	被引频次：10[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/321006/35368
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Y. L. Hao,R. Yang,Y. Song,et al. Formation of point defects in TiAl and NiAl[J]. Intermetallics,2004,12(7-9):951-956.
APA	Y. L. Hao,R. Yang,Y. Song,Y. Y. Cui,D. Li,&A. Niinomi.(2004).Formation of point defects in TiAl and NiAl.Intermetallics,12(7-9),951-956.
MLA	Y. L. Hao,et al."Formation of point defects in TiAl and NiAl".Intermetallics 12.7-9(2004):951-956.