首页 | 本学科首页   官方微博 | 高级检索  
     检索      

Nb元素影响TiAl金属间化合物键合特征的第一原理计算
引用本文:吴红丽,张伟,宫声凯.Nb元素影响TiAl金属间化合物键合特征的第一原理计算[J].化学学报,2008,66(14):1669-1675.
作者姓名:吴红丽  张伟  宫声凯
作者单位:1. 北京航空航天大学材料科学与工程学院,北京,100083
2. 利兹大学机械工程学院 英国利兹 LS2 9JT
摘    要:采用第一原理方法, 研究了Nb元素对TiAl金属间化合物电子结构及其对Ti, Al和O原子键合作用的影响. 研究结果表明, Nb元素对富Ti和富Al的TiAl金属间化合物体系电子结构及键合作用的影响不同. 对于富Ti的TiAl金属间化合物体系, Nb原子取代Ti晶格位置后, 减小了Ti费米能级处的电子密度, 削弱了Ti原子与O原子间的相互作用; 同时增强了Al原子中s电子和O原子中p电子的相互作用. 而Nb原子对富Al的TiAl金属间化合物体系中Ti/Al与O的相互作用影响较小. 同时, 向TiAl金属间化合物中掺杂Nb元素, 增大了TiO2的生成能垒, 减小了Al2O3的生成能垒, 有利于促进抗氧化膜Al2O3的生成. 因此, 添加合金化元素Nb有利于提高TiAl金属间化合物的抗氧化性能, 这与实验报道相一致.

关 键 词:TiAl金属间化合物  氧化性能  Nb元素  电子结构  第一原理计算
收稿时间:2008-1-14
修稿时间:2008-3-10

Effect of Nb on the Bonding Characteristics of TiAl Intermetallic Compounds: A First-principle Study
WU Hong-Li,ZHANG Wei,GONG Sheng-Kai.Effect of Nb on the Bonding Characteristics of TiAl Intermetallic Compounds: A First-principle Study[J].Acta Chimica Sinica,2008,66(14):1669-1675.
Authors:WU Hong-Li  ZHANG Wei  GONG Sheng-Kai
Institution:(a School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China)
(b Mechanical Engineering, University of Leeds, LS2 9JT, UK)
Abstract:First-principle calculations were performed to study the effect of Nb on the bonding characteristics of TiAl intermetallic compounds with the emphasis on the electronic interactions between Ti (Al) and O atoms. The calculation results suggest that Nb impose different influence on the electronic structure of Ti-riched and Al-riched TiAl intermetallic compounds. For the Ti-riched alloy, Nb not only reduces the electron density of Ti atom near Fermi energy level, but also enhances the interactions between Al (s) electrons and O (p) electrons. By contrast, Nb has marginal effect on the bonding characteristics of the Al-riched TiAl alloy. With the introduction of Nb, the formation energy barrier of TiO2 is increased, while the generation of anti-oxidation membrane (Al2O3) is facilitated due to the decrease of the formation energy barrier. Both aspects are beneficial to improve the oxidation resistance of the TiAl alloy, which is consistent with the experimental results.
Keywords:TiAl intermetallic compound  oxidation property  element Nb  electronic structure  first-principle calculation
本文献已被 维普 万方数据 等数据库收录!
点击此处可从《化学学报》浏览原始摘要信息
点击此处可从《化学学报》下载免费的PDF全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号