物理化学学报Issue(2)：289-296,8.DOI:10.3866/PKU.WHXB201312191
Ti，Cr，Al和B合金化元素对α-Nb5Si3力学性能和电子结构的影响
Effects of the Alloying Elements Ti, Cr, Al and B on the Mechanical Properties and Electronic Structure ofα-Nb5Si3
摘要
Abstract
The structural stability and mechanical properties ofα-Nb5Si3 al oyed with Ti, Cr, Al and B were investigated using first-principles methods based on density functional theory (DFT) by comparing the formation energy, valence electron concentrations, elastic constants, the shear modulus/bulk modulus ratio, and the Peierls stress. The results show that the structures of theα-Nb5Si3 al oys retain the stable D81 structure, in which the al oying elements Ti, Cr, Al and B prefer to occupy the Nb4c, Nb4c, Si4a and Si8h sites ofα-Nb5Si3, respectively. The addition of Ti, Al and B increase the brittleness of D81 structuredα-Nb5Si3, while Cr addition is beneficial to the toughness ofα-Nb5Si3. Moreover, the influence of the al oying elements on the ductility/brittleness ofα-Nb5Si3 was investigated based on analysis of the electronic structure, density of states and Mul iken population. The increased brittleness ofα-Nb5Si3 by the addition of Ti, Al and B can be attributed to enhanced orientation of the covalent bonds, whereas Cr addition weakens the number and strength of covalent bonds and more anti-bonding states are occupied, thus improving the toughness.关键词
第一性原理/铌硅化合物/结构稳定性/韧/脆性/电子结构Key words
First-principles/Niobium-silicon compound/Structural stability/Ductile/brittle behavior/Electronic structure分类
化学化工引用本文复制引用
邹爱华,徐江,黄豪杰..Ti，Cr，Al和B合金化元素对α-Nb5Si3力学性能和电子结构的影响[J].物理化学学报,2014,(2):289-296,8.基金项目
The project was supported by the National Natural Science Foundation of China (51374130) and Aeronautical Science Foundation of China (2013ZE52058)@@@@国家自然科学基金(51374130)和航空科学基金(2013ZE52058)资助项目 （51374130）
