Cr含量对Fe3Al合金电子结构及力学性能影响的第一性原理

采用基于密度泛函理论的第一性原理方法研究了Cr含量对DO3-Fe3 Al合金电子结构及力学性能的影响.通过计算掺杂前后体系的形成热和结合能明确Cr在超晶胞模型中的占位;通过计算各体系的弹性模量、布居、态密度及差分电荷密度揭示了Cr对Fe3 Al合金力学性能影响的微观机制.结果表明:含量为3.125 at.％时,Cr优先...

First principles on the effect of Cr content on the electronic structure and mechanical properties of Fe3 Al alloy

Effect of Cr content on the electronic structure and mechanical properties of DO₃-Fe₃al alloy was investigated by using the first principle method based on density functional theory. The occupation of Cr in the supercell model was determined by calculating the formation heat and binding energy of the system before and after doping, and the micro mechanism of the effect of Cr on the mechanical properties of Fe₃Al alloy was revealed by calculating the elastic modulus, population, density of states and differential charge density. The results showed that Fe Ι bit is preferentially occupied when the Cr content is 3.125 at.%, while the content is 6.25 at.%), it tends to occupy Fe Ι and Al bit. The doping of Cr improves the stability of the system and the brittleness of the alloy, and the toughening effect increases with the increase of Cr content. Cr doping changes the distribution of electrons between atoms, with the increase of Cr content, the number of p-d hybrid electrons between Fe and Al decreases and the covalent bond decreases, at the same time, the charge transferring between atoms increases, the increase of Fe-Fe bond and the existence of Fe-Cr and Al-Cr anti bonds enhance the metallicity of the system, in addition, decrease of the covalent bond on the (100) plane but the increases of bonding strength between atoms on the (010) plane are all the essential reasons that the addition of Cr can improve the toughness of Fe₃Al alloy.