Advanced   Register
IMR OpenIR  > 中国科学院金属研究所  > 期刊论文

题名: On the abnormal fast diffusion of solute atoms in alpha-Ti: A first-principles investigation
作者: Zhang, LJ;  Chen, ZY;  Hu, QM;  Yang, R
发表日期: 2018-4-5
摘要: Solute atoms such as Fe, Co, and Ni diffuse abnormally fast in alpha-Ti, which influences significantly the mechanical properties of the titanium alloys. Various mechanisms (e.g., the interstitial diffusion mechanism and solute-vacancy complex mechanism) have been proposed to account for the fast diffusion of these solutes in alpha-Ti. To elucidate such diffusion mechanism, a first-principles method is employed to calculate the formation energies, migration energy barriers, and solute-vacancy binding energies of the substitutional and interstitial solute atoms including Al, Si, Sn, V, Mn, Fe, Co, Ni, and Cu in alpha-Ti. Based on the calculated parameters, the diffusion mechanisms are discussed. Comparing the formation energies of the substitutional and interstitial solutes, we find that all the solute atoms prefer the substitutional configuration to the interstitial one. The interstitial migration energy barriers are quite low for all the solutes. Al and Sn diffuse mainly through normal vacancy mediated mechanism due to the high substitutional to interstitial preferential energy that leads to very low fraction of interstitial solutes (about 10(-15) similar to 10(-16) at 1000 K) at thermal equilibrium state and high interstitial diffusion activation energy. The 3d metal solute atoms, especially Mn, Fe, and Co, are fast diffusers and the diffusion coefficients are dominated by the interstitial mechanism because of their sizable thermal equilibrium interstitial fractions (several percent at 1000 K). The solute-vacancy complex mechanism is not likely to account for the fast diffusions in alpha-Ti. We show that the direct chemical interaction between the solute and matrix atoms determines the site-occupancy of the solute atoms in alpha-Ti besides the atomic size effect that was commonly believed to be responsible for the fast diffusions. (C) 2018 Elsevier B.V. All rights reserved.
Appears in Collections:中国科学院金属研究所_期刊论文

Files in This Item:

There are no files associated with this item.

Recommended Citation:
Zhang, LJ,Chen, ZY,Hu, QM,et al. On The Abnormal Fast Diffusion Of Solute Atoms In Alpha-ti: A First-principles Investigation[J]. Journal Of Alloys And Compounds,2018,740:156-166.

SCI Citaion Data:
 Recommend this item
 Sava as my favorate item
 Show this item's statistics
 Export Endnote File
Google Scholar
 Similar articles in Google Scholar
 [Zhang, LJ]'s Articles
 [Chen, ZY]'s Articles
 [Hu, QM]'s Articles
CSDL cross search
 Similar articles in CSDL Cross Search
 [Zhang, LJ]‘s Articles
 [Chen, ZY]‘s Articles
 [Hu, QM]‘s Articles
Scirus search
 Similar articles in Scirus
Related Copyright Policies
Social Bookmarking
  Add to CiteULike  Add to Connotea  Add to  Add to Digg  Add to Reddit 
所有评论 (0)
内 容:
Email:  *
验证码:   刷新
标 题:
内 容:
Email:  *
验证码:   刷新

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.



Valid XHTML 1.0!
Copyright © 2007-2018  中国科学院金属研究所  -Feedback
Powered by CSpace