Transactions of Nonferrous Metals Society of China The Chinese Journal of Nonferrous Metals

您目前所在的位置:首页 - 期刊简介 - 详细页面

中国有色金属学报

ZHONGGUO YOUSEJINSHU XUEBAO

第24卷    第11期    总第188期    2014年11月

[PDF全文下载]    [Flash在线阅读]    

    

文章编号:1004-0609(2014)11-2789-09
金属间化合物L10-TiAl点缺陷浓度的第一原理
陶辉锦1, 2,孙顺平3,张铖铖1,陈 图1,罗 伟1,江 勇1, 2

(1. 中南大学 材料科学与工程学院,长沙 410083;
2. 中南大学 有色金属材料科学与工程教育部重点实验室,长沙 410083;
3. 江苏理工学院 材料工程学院,常州 213001
)

摘 要: 采用第一原理平面波赝势方法,结合Wagner-Schottky缺陷热力学模型,研究金属间化合物L10-TiAl中各种空位和反位点缺陷的形成焓、热力学平衡浓度及其相互作用等。结果表明:这些缺陷的热力学平衡浓度均随温度的升高而增大,其中反位缺陷浓度均高于空位缺陷浓度,Ti空位浓度高于Al空位浓度。在理想化学计量比成分下,Ti反位缺陷的浓度与Al反位缺陷的基本相当;在略偏离计量比的富Ti成分端,Ti反位缺陷的浓度高于Al反位缺陷的;在富Al成分端则相反。不同点缺陷之间均普遍存在相互排斥性,难以聚集,将倾向于向基体中分散和扩散。

 

关键词: L10-TiAl金属间化合物;点缺陷浓度;形成焓;第一原理;Wagner-Schottky模型

First principles of point defect concentrations in L10-TiAl intermetallic composite
TAO Hui-jin1, 2, SUN Shun-ping3, ZHANG Cheng-cheng1, CHEN Tu1, LUO Wei1, JIANG Yong1, 2

1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering,
Ministry of Education, Central South University, Changsha 410083, China;
3. School of Materials Engineering, Jiangsu University of Technology, Changzhou 213001, China

Abstract:Using the plane wave pseudopotential method in first-principles and Wagner-Schottky model, the formation enthalpies, equilibrium concentrations, and interaction of vacancies and anti-site point defects were assessed for L10-TiAl intermetallics. The results show that, in the whole composition range of interest, all the defect concentrations increase with increasing temperature. In particular, the anti-site defect concentrations are higher than the vacancy defect concentrations, and the Ti vacancy concentration is higher than the Al vacancy concentration. At the stoichiometric composition, the Ti anti-site defect concentration is comparable to that of Al anti-site defect. At the Ti-rich side, the Ti anti-site defect concentration is higher than that of Al anti-site defect, while at the Al-rich side, the Al anti-site defect concentration is higher than that of Ti anti-site defect. The interaction between these defects is essentially repulsive, which facilitates the defect distribution and diffusion in the matrix.

 

Key words: L10-TiAl intermetallic composite; point defect concentration; formation enthalpy; first principles; Wagner-Schottky model

ISSN 1004-0609
CN 43-1238/TG
CODEN: ZYJXFK

ISSN 1003-6326
CN 43-1239/TG
CODEN: TNMCEW

主管:中国科学技术协会 主办:中国有色金属学会 承办:中南大学
湘ICP备09001153号 版权所有:《中国有色金属学报》编辑部
------------------------------------------------------------------------------------------
地 址:湖南省长沙市岳麓山中南大学内 邮编:410083
电 话:0731-88876765,88877197,88830410   传真:0731-88877197   电子邮箱:f_ysxb@163.com