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为了研究FeAl金属间化合物的脆性,采用第一性原理计算方法,建立了FeAl超晶胞模型,对H原子掺杂前后的FeAl的电子结构进行计算。计算结果显示:在B2型金属间化合物FeAl中,Al原子的sp杂化轨道具有较强的方向性,参与形成的FeAl之间pd极化键导致了晶体的脆性。在H原子掺杂浓度为1.82%的情况下,FeAl体系中置入H原子,与H原子近邻的Al原子状态发生改变,更多的晶格电子为了与H原子成键,转化为共价电子,使晶体内局域金属性下降。由于H原子参与成键,晶体内形成具有明显各向异性的键络,更易于解理。
In order to study the brittleness of FeAl intermetallic compounds, the first-principles calculation method was used to establish the FeAl superlattice model to calculate the electronic structure of FeAl before and after H doping. The results show that in the B2 type intermetallic compound FeAl, the sp hybridization orbitals of Al atoms have a strong directivity, and the polarization of pd between the formed FeAl leads to the brittleness of the crystal. In the case of a H atom doping concentration of 1.82%, the H atom is placed in the FeAl system and the Al atom adjacent to the H atom changes state. More lattice electrons are converted to covalent electrons in order to bond with the H atom , So that the local intracrystalline metal decreased. Since H atoms participate in the formation of bonds, the crystal forms a significant anisotropy of the bond network, making cleavage easier.