Site Occupation of Nb in gamma-TiAl: Beyond the Point Defect Gas Approximation

doi:10.1007/s40195-019-00925-z

IMR OpenIR

	Site Occupation of Nb in gamma-TiAl: Beyond the Point Defect Gas Approximation
	Diao, Wei 1,2; Ye, Li-Hua 1; Ji, Zong-Wei 1,3; Yang, Rui 1; Hu, Qing-Miao 1
通讯作者	Hu, Qing-Miao(qmhu@imr.ac.cn)
	2019-12-01
发表期刊	ACTA METALLURGICA SINICA-ENGLISH LETTERS
ISSN	1006-7191
卷号	32 期号:12 页码:1511-1520
摘要	Microalloying is an effective approach to improve the mechanical properties of gamma -TiAl intermetallic compound. Knowledge about the site occupancy of the ternary alloying element in the crystal lattice of gamma -TiAl is highly demanded in order to understand the physics underlying the alloying effect. Previous first-principle methods-based thermodynamic models for the determination of the site occupancy were based on the point defect gas approximation with the interaction between the point defects neglected. In the present work, we include the point defect interaction energy in the thermodynamic model, which allows us to predict the site occupancy of the ternary alloying element in gamma -TiAl beyond the point defect gas approximation. The model is applied to the gamma -TiAl-Nb alloy. We show that, at low temperature, the site occupancy of Nb atoms depends on the composition of the alloy: Nb atoms occupy the Al sublattice for the Ti-rich alloy but occupy Ti sublattice for the Al-rich alloy. The fraction of Nb atoms occupying Al sublattice in the Ti-rich alloy decreases drastically, whereas the fraction of Nb atoms on the Ti sublattice in the Al-rich alloy decreases slightly with increasing temperature. At high temperature, Nb atoms occupy dominantly the Ti sublattice for both the Ti-rich and Al-rich alloys. The interaction between the point defects makes the Ti sublattice more favorable for the Nb atoms to occupy.
关键词	Site preference Titanium aluminides Special quasi-random structures First principles method
资助者	National Key Research and Development Program of China ; National Natural Science Foundation of China
DOI	10.1007/s40195-019-00925-z
收录类别	SCI
语种	英语
资助项目	National Key Research and Development Program of China[2016YFB0701301] ; National Natural Science Foundation of China[91860107]
WOS研究方向	Metallurgy & Metallurgical Engineering
WOS类目	Metallurgy & Metallurgical Engineering
WOS记录号	WOS:000495116000008
出版者	CHINESE ACAD SCIENCES, INST METAL RESEARCH
引用统计	被引频次：5[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/321006/137031
专题	中国科学院金属研究所
通讯作者	Hu, Qing-Miao
作者单位	1.Chinese Acad Sci, Inst Met Res, Wenhua Rd 72, Shenyang 110016, Liaoning, Peoples R China 2.Univ Sci & Technol China, Sch Mat Sci & Engn, Jinzhai Rd 96, Hefei 230026, Anhui, Peoples R China 3.Univ Chinese Acad Sci, Yuquan Rd 19A, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Diao, Wei,Ye, Li-Hua,Ji, Zong-Wei,et al. Site Occupation of Nb in gamma-TiAl: Beyond the Point Defect Gas Approximation[J]. ACTA METALLURGICA SINICA-ENGLISH LETTERS,2019,32(12):1511-1520.
APA	Diao, Wei,Ye, Li-Hua,Ji, Zong-Wei,Yang, Rui,&Hu, Qing-Miao.(2019).Site Occupation of Nb in gamma-TiAl: Beyond the Point Defect Gas Approximation.ACTA METALLURGICA SINICA-ENGLISH LETTERS,32(12),1511-1520.
MLA	Diao, Wei,et al."Site Occupation of Nb in gamma-TiAl: Beyond the Point Defect Gas Approximation".ACTA METALLURGICA SINICA-ENGLISH LETTERS 32.12(2019):1511-1520.