First-Principles Study on Free Energy and Elastic Properties of Disordered beta-Ti1-xNbx Alloy: Comparison Between SQS and CPA

doi:10.11900/0412.1961.2020.00015

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	First-Principles Study on Free Energy and Elastic Properties of Disordered beta-Ti1-xNbx Alloy: Comparison Between SQS and CPA
	Zhang Haijun 1,3; Qiu Shi 2; Sun Zhimei 2; Hu Qingmiao 3; Yang Rui 3
刊名	ACTA METALLURGICA SINICA
	2020-09-01
卷号	56 期号:9 页码:1304-1312
关键词	titanium alloy random solid solution special quasirandom structure coherent potential approximation elastic constant first-principles calculation
ISSN号	0412-1961
DOI	10.11900/0412.1961.2020.00015
通讯作者	Hu Qingmiao(qmhu@imr.ac.cn)
英文摘要	Elastic modulus is one of the key properties for the application of biomedical beta titanium alloy as human bone replacement because the elastic modulus of the alloy has to match that of the bone so as to avoid the stress shielding effect. Alloying of Nb is commonly used in biomedical beta titanium alloys. In the present work, the lattice parameter, free energy and elastic modulus of beta-Ti1-xNbx alloy were investigated by using first-principles method based on density functional theory. The random distribution of Nb atoms in the alloy were described by using both special quasirandom structure (SQS) and the coherent potential approximation (CPA) techniques, in combination with first principles plane-wave pseudopotential (VASP) and exact muffin-tin orbital (EMTO) methods, respectively. The results showed that the lattice constants from both VASP-SQS and EMTO-CPA calculations increase linearly with Nb content x, while the influence of the local lattice distortion is negligible. The calculations of the free energies demonstrated that EMTO-CPA predicts reasonably the phase decomposition of beta-Ti(1-x)Nb(x )at relatively low temperature whereas VASP-SQS does not, which might be ascribed to the fact that the free energy depends strongly on the detailed SQS structures. The elastic constants C-11 and C-22 calculated by using EMTO-CPA and VASP-SQS without atomic relaxation increase with Nb content whereas C-44 decreases. EMTO-CPA overestimates the elastic stability of beta-Ti1-xNbx.At- low Nb content, the local lattice distortion is abnormally large due to the lattice instability of the beta-Ti(1-x)Nb(x, )making the free energy and elastic constant against x from VASP-SQS calculations with atomic relaxation deviate significantly from the general trend.
资助项目	National Key Research and Development Program of China[2016YFB0701301] ; National Natural Science Foundation of China[91860107] ; National Basic Research Program of China[2014CB644001]
WOS研究方向	Metallurgy & Metallurgical Engineering
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000576758600013
资助机构	National Key Research and Development Program of China ; National Natural Science Foundation of China ; National Basic Research Program of China
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/140897]
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.Univ Sci & Technol China, Sch Mat Sci & Engn, Shenyang 110016, Peoples R China 2.Beihang Univ, Sch Mat Sci & Engn, Beijing 100191, Peoples R China 3.Chinese Acad Sci, Inst Met Res, Shenyang 110016, Peoples R China
推荐引用方式 GB/T 7714	Zhang Haijun,Qiu Shi,Sun Zhimei,et al. First-Principles Study on Free Energy and Elastic Properties of Disordered beta-Ti1-xNbx Alloy: Comparison Between SQS and CPA[J]. ACTA METALLURGICA SINICA,2020,56(9):1304-1312.
APA	Zhang Haijun,Qiu Shi,Sun Zhimei,Hu Qingmiao,&Yang Rui.(2020).First-Principles Study on Free Energy and Elastic Properties of Disordered beta-Ti1-xNbx Alloy: Comparison Between SQS and CPA.ACTA METALLURGICA SINICA,56(9),1304-1312.
MLA	Zhang Haijun,et al."First-Principles Study on Free Energy and Elastic Properties of Disordered beta-Ti1-xNbx Alloy: Comparison Between SQS and CPA".ACTA METALLURGICA SINICA 56.9(2020):1304-1312.