5d过渡金属掺杂γ-TiAl合金的第一性原理研究  

First-principles Investigation on Site Substitution of 5d Transition Metals in γ-TiAl Alloy

作　　者：刘显坤[1] 郑洲[1] 刘聪[1] 兰晓华[1] 尹伟[1] 

机构地区：[1]中国工程物理研究院核物理与化学研究所,绵阳621900

出　　处：《材料导报》2012年第24期115-119,136,共6页Materials Reports

基　　金：国防预研项目(20100210);中国工程物理研究院科学发展基金(2010B0103008)

摘　　要：采用基于密度泛函理论的第一性原理平面波赝势方法,系统地研究了5d过渡金属在γ-TiAl合金中的占位及占位方式,获得了过渡金属掺杂合金体系的形成能、几何结构、电子结构及电荷布居值等参数。结果表明:5d过渡金属元素Hf、Ta和W优先占据γ-TiAl合金中的Ti位;Os、Ir、Pt、Au等优先占据Al位;Re则既有占据Ti位的可能,也有占据Al位的可能,但占据Al位的趋势略大。通过对不同元素掺杂体系的能带结构、态密度和电荷布居值的计算和分析,进一步验证了不同过渡金属元素在TiAl合金中的占位规律,解释了5d过渡金属掺杂对TiAl合金体系结构和性能的影响。Site substitutions of 5d transition metal elements in T-TiAl alloy were investigated by first-principle plane-wave pseudopotential method based on density functional theory （DFT）. The formation energy, geometric and electronic structure, and Mulliken population were obtained. The results show that Hf, Ta and W mainly substitute for Ti in 3＇-TiAI alloy, and Os, Ir, Pt and Au preferentially substitute for Al in γ-TiAl alloy. Re has two substitution possibilities in γ-TiAl alloy--Ti and Al site, but the preference for substitution at Al site is a little stronger. Through the calculation and analysis for band structure, density of state, and Mulliken population in systems substituted by various elements, the site substitution disciplinarians were confirmed, and the effects on structure and performance of TiAl alloy were explained.

关 键 词：TIAL金属间化合物 第一性原理 占位 电子结构 

分 类 号：TG146.2[一般工业技术—材料科学与工程]