C,Fe,Si掺杂Al_(3)V合金的电子结构与力学性能

Electronic structure and mechanical properties of C, Fe, Si doped Al_(3)V alloy

采用第一性原理计算方法研究了铝钒合金Al_(3)V及其C、Fe、Si取代掺杂的Al_(24)V_(7)X、Al_(23)V_(8)X (X=C,Fe,Si)合金晶体结构的稳定性、电子结构和力学性能。计算结果表明,X (X=C,Fe,Si)掺杂对Al_(3)V合金晶体结构的影响较小,Al_(24)V_(7)X和Al_(23)V_(8)X (X=C,Fe,Si)仍然保持明显的Al_(3)V金属特征。Mulliken电荷布居和重叠布居分析显示X (X=C,Fe,Si)会与周围Al和V原子产生键合作用,提高Al_(24)V_(7)X和Al_(23)V_(8)X (X=C,Fe,Si)的稳定性和抗变形能力。X (X=C,Fe,Si)的取代掺杂对Al_(3)V合金晶体的刚度影响较小,但能使Al_(3)V合金材料的塑性有所提升,有望能有效解决Al_(3)V合金的脆性问题,拓宽Al_(3)V合金的应用范围。

The crystal structure stabilities, electronic structures and mechanical properties of Al_(3)V alloy and its substituted structures Al_(24)V_(7)X and Al_(23)V_(8)X (X=C, Fe, Si) were explored by the first-principles calculations. The calculation results show that X(X=C, Fe, Si) doping has slight influence on the crystal structure of Al_(3)V alloy, and Al_(24)V_(7)X and Al_(23)V_(8)X (X=C, Fe, Si) still maintain obvious metal characteristics of Al_(3)V alloy. The Mulliken population and overlapping population analysis results show that the X(X=C, Fe, Si) bond with the adjacent Al and V atoms, which in turn improves the stability and anti-deformation capability of Al_(24)V_(7)X and Al_(23)V_(8)X (X=C,Fe, Si). The doping of X(X=C, Fe, Si) not only has slight influence on the rigidity of Al_(3)V alloy, but also can improve the plasticity, which is expected to effectively solve the brittleness issue of Al_(3)V alloy and broaden the application range.