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

doi:10.11900/0412.1961.2018.00349

IMR OpenIR

	First-Principles Study on the Impact of Antisite Defects on the Mechanical Properties of TiAl-Based Alloys
	Ji Zongwei 1,2,3; Lu Song 3; Yu Hui 1,4; Hu Qingmiao 1; Levente, Vitos 3; Yang Rui 1
通讯作者	Hu Qingmiao(qmhu@imr.ac.cn)
	2019-05-11
发表期刊	ACTA METALLURGICA SINICA
ISSN	0412-1961
卷号	55 期号:5 页码:673-682
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.
关键词	antisite defect TiAl-based alloy generalized stacking fault energy plastic deformation
资助者	National Basic Research Program of China ; National Key Research and Development Program of China
DOI	10.11900/0412.1961.2018.00349
收录类别	SCI
语种	英语
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
WOS类目	Metallurgy & Metallurgical Engineering
WOS记录号	WOS:000464751100014
出版者	SCIENCE PRESS
引用统计	被引频次：3[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/321006/132712
专题	中国科学院金属研究所
通讯作者	Hu Qingmiao
作者单位	1.Chinese Acad Sci, Inst Met Res, Shenyang 110016, Liaoning, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Royal Inst Technol, Dept Mat Sci & Engn, Appl Mat Phys, SE-10044 Stockholm, Sweden 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.