Cr、Mo对DO3-Fe3Al力学性能和电子结构影响的理论研究

Theoretical research on the effect of Cr, Mo on the mechanical properties and electronic structure of DO3-Fe3Al

摘要:

采用基于密度泛函理论的第一性原理方法,研究了Cr、Mo在DO₃-Fe₃Al 金属间化合物中的占位、以及Cr、Mo对Fe₃Al力学性能和电子结构的影响。研究显示：Cr、Mo在Fe₃Al中优先替代Al原子；Cr、Mo的添加均提升了Fe₃Al的体模量、剪切模量、弹性模量以及塑性,其中Mo对Fe₃Al的模量以及塑性的提升效果更明显。电子结构和电荷密度分析表明：Cr、Mo对Fe₃Al力学性能提高的主要原因是Cr、Mo的s,p和d轨道电子参与了Fe₃Al的电子杂化,Cr、Mo增加了Fe₃Al的成键峰数量,且增加了Fe₃Al中原子间的重叠电子数,此外Cr、Mo减弱了Fe₃Al中Fe-Fe间电子云的方向性。

Abstract:

The preferred site of Cr or Mo alloying element in the DO₃-Fe₃Al intermetallic compounds, and the effect of Cr or Mo on the mechanical properties and electronic structure of Fe₃Al are investigated by first-principle based on density functional theory. The research demonstrated that Cr or Mo preferred substitutes the Al atom in Fe₃Al, and Cr or Mo increases the bulk moduli, rigidity moduli and Young"s modulus of Fe₃Al and improves the ductility of Fe₃Al. According to the analysis of the electronic structure and the electronic density, the effect on improving the mechanical properties of Fe₃Al can be mainly attributed to the s, p, d-state orbital electron of the element Cr or Mo dropped is involved in hybridization of Fe₃Al, Cr or Mo has increased the number of the bonding peaks of Fe₃Al and overlapping electron number among atoms of Fe₃Al, in addition, Cr or Mo decrease the directionality of electron atmosphere between Fe-Fe of Fe₃Al.