Electronic structure and physical properties of hcp Ti₃Al type alloys

来源期刊：中国有色金属学报(英文版)2007年第4期

论文作者：彭红建 谢佑卿

文章页码：766 - 766

Key words：Ti₃Al alloy; electronic structure; physical property

Abstract: Abstract: According to the basic information of sequences of Ti and Al characteristic atoms in hcp Ti-Al system, the compositional variations of the electronic structure, atomic potential energies, atomic volumes, lattice constants and cohesive energies of the ordered hcp Ti₃Al type alloys were calculated by the framework of systematic science of alloys(SSA). The electronic structure of the hcp Ti₃Al compound consisted of and atoms is 0.75[Ar] (3d_n)^0.573(3d_c)^2.1685(4s_c)^0.972(4s_f)^0.3093+0.25[Ne](3s_c)^1.32？ (3p_c)^1.19(3s_f)^0.49. The factors of controlling lattice stability are electronic structure, atomic energies and atomic concentration. The atoms play a determinative role in forming D0₁₉ structure with a=0.287 2 nm, c=0.456 4 nm, atomic cohesive energy ε=4.810 8 eV/atom and heat of formation ΔH=-0.332 8 eV/atom. These calculated values are in good agreement with experimental values (a=0.287 5 nm, c=0.46 0 nm, ？H=-0.27, -0.29 eV/atom). The calculated cohesive energy of the hcp Ti₃Al compound is slightly bigger than that of the fcc Ti₃Al.This is a good sign that makes it feasible to stabilized L1₂ structure of the hcp Ti₃Al compound by ternary element. The new element should have more d_c-electrons than Ti-metal and occupy at the Ti-lattice points.

基金信息：the National Natural Science Foundation of China
the Natural Science Foundation of Hunan Province, China