First-Principles Study on the Impact of Antisite Defects on the Mechanical Properties of TiAl-Based Alloys

doi:10.11900/0412.1961.2018.00349

CORC > 金属研究所 > 中国科学院金属研究所

	First-Principles Study on the Impact of Antisite Defects on the Mechanical Properties of TiAl-Based Alloys
	Ji Zongwei 1,2,3; Lu Song 1; Yu Hui 2,4; Hu Qingmiao 2; Levente, Vitos 1; Yang Rui 2
刊名	ACTA METALLURGICA SINICA
	2019-05-11
卷号	55 期号:5 页码:673-682
关键词	antisite defect TiAl-based alloy generalized stacking fault energy plastic deformation
ISSN号	0412-1961
DOI	10.11900/0412.1961.2018.00349
通讯作者	Hu Qingmiao(qmhu@imr.ac.cn)
英文摘要	Microalloying is an effective approach to improve the mechanical properties of TiAl-based alloys which have been applied as high-temperature structure materials. The antisite defects may be regarded as special alloying elements. However, the detailed information about the effect of antisite defects on mechanical behavior (full slip and twinning), which may be described theoretically by generalized stacking fault energy (GSFE), of TiAl-based alloys are scarce. In this work, the composition dependent GSFEs of off-stoichiometric gamma- TiAl were calculated by using the first-principles exact muffin-tin orbitals method in combination with coherent potential approximation. With the calculated GSFE, the energy barriers for various deformation modes including twin (TW), ordinary dislocation (OD), and superlattice dislocation (SDI and SDII) were determined. The selection of the deformation mode under external shear stress with various directions was analyzed. The effects of the Ti-Al and Al(Ti )antisite defects on the mechanical properties of gamma-TiAl were then discussed. The results showed that the Ti-Al antisite defect decreases the energy barrier for the TW deformation leading by the superlattice intrinsic stacking fault (SISF) partial dislocation and increases the angle window of the applied shear stress within which TW deformation may be activated. Therefore, Ti-Al antisite defect is expected to improve the plasticity of gamma-TiAl. The effect of Al-Ti antisite defect is opposite. The Al-Ti antisite defect decreases the energy barriers for the OD and SDII deformations leading by complex stacking fault (CSF) partial dislocation and increases their operating angle window, indicating that Al-Ti facilitates the slip of OD and SDII. Considering that the energy barrier for CSF is much higher than that for SISF, the plasticity induced by OD and SDII should be lower than that induced by TW. Calculations in this work explain the experimental finding that Ti-Al antisite defect improves the plasticity of gamma-TiAl more significantly than Al-Ti antisite defect.
资助项目	National Basic Research Program of China[2014CB644001] ; National Key Research and Development Program of China[2016YFB0701301]
WOS研究方向	Metallurgy & Metallurgical Engineering
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000464751100014
资助机构	National Basic Research Program of China ; National Key Research and Development Program of China
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/132709]
专题	金属研究所_中国科学院金属研究所
通讯作者	Hu Qingmiao
作者单位	1.Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden 2.Chinese Acad Sci, Inst Met Res, Shenyang 110016, Liaoning, Peoples R China 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 4.Shenyang Univ Technol, Sch Informat Sci & Engn, Shenyang 110870, Liaoning, Peoples R China
推荐引用方式 GB/T 7714	Ji Zongwei,Lu Song,Yu Hui,et al. First-Principles Study on the Impact of Antisite Defects on the Mechanical Properties of TiAl-Based Alloys[J]. ACTA METALLURGICA SINICA,2019,55(5):673-682.
APA	Ji Zongwei,Lu Song,Yu Hui,Hu Qingmiao,Levente, Vitos,&Yang Rui.(2019).First-Principles Study on the Impact of Antisite Defects on the Mechanical Properties of TiAl-Based Alloys.ACTA METALLURGICA SINICA,55(5),673-682.
MLA	Ji Zongwei,et al."First-Principles Study on the Impact of Antisite Defects on the Mechanical Properties of TiAl-Based Alloys".ACTA METALLURGICA SINICA 55.5(2019):673-682.