Effects of Nb and Si on densities of valence electrons in bulk and defects of Fe3Al alloys

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	Effects of Nb and Si on densities of valence electrons in bulk and defects of Fe3Al alloys
	W. Deng; X. P. Zhong; Y. Y. Huang; L. Y. Xiong; S. H. Wang; J. T. Guo; Q. W. Long
	1999
发表期刊	Science in China Series a-Mathematics Physics Astronomy
ISSN	1006-9283
卷号	42 期号:1 页码:87-92
摘要	Positron lifetime measurements have been performed in binary Fe3Al and Fe3Al doping with Nb or Si alloys. The densities of valence electrons of the bulk and microdefects in all tested samples have been calculated by using the positron lifetime parameters. Density of valence electron is low in the bulk of Fe3Al alloy. It indicates that, the 3d electrons in a Fe atom have strong-localized properties and tend to form covalent bonds with Al atoms, and the bonding nature in Fe3Al is a mixture of metallic and covalent bonds. The density of valence electron is very low in the defects of Fe3Al grain boundary, which makes the bonding cohesion in grain boundary quite weak. The addition of Si to Fe3Al gives rise to the decrease of the densities of valence electrons in the bulk and the grain boundary thus the metallic bonding cohesion. This makes the alloy more brittle. The addition of Nb to Fe3Al results in the decrease of the ordering energy of the alloy and increases the density of valence electron and the bonding cohesion of the grain boundary. However, since the radius of Nb atom is larger than that of Fe atom, when Nb atoms substitute for Fe atoms, they will distort the lattice and enlarge the volume of the lattice, which decreases the density of valence electron and the cohesion of metallic bond in the bulk of the alloy.
部门归属	guangxi univ, dept phys, nanning 530004, peoples r china. acad sinica, int ctr mat phys, met res inst, shenyang 110015, peoples r china.;deng, w (reprint author), guangxi univ, dept phys, nanning 530004, peoples r china
关键词	Positron Lifetime Fe3al Alloy Alloying Element Microdefect Density Of Valence Electron Positron Fracture
URL	查看原文
WOS记录号	WOS:000078523500011
引用统计	被引频次：11[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/321006/37343
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	W. Deng,X. P. Zhong,Y. Y. Huang,et al. Effects of Nb and Si on densities of valence electrons in bulk and defects of Fe3Al alloys[J]. Science in China Series a-Mathematics Physics Astronomy,1999,42(1):87-92.
APA	W. Deng.,X. P. Zhong.,Y. Y. Huang.,L. Y. Xiong.,S. H. Wang.,...&Q. W. Long.(1999).Effects of Nb and Si on densities of valence electrons in bulk and defects of Fe3Al alloys.Science in China Series a-Mathematics Physics Astronomy,42(1),87-92.
MLA	W. Deng,et al."Effects of Nb and Si on densities of valence electrons in bulk and defects of Fe3Al alloys".Science in China Series a-Mathematics Physics Astronomy 42.1(1999):87-92.