为了预测Mg微合金化对MoSi2性能的影响,运用固体与分子经验电子理论（EET）,采用键距差（BLD）以及平均原子模型的方法,对MoSi2和Mo（Si0.95,Mg0.05）2固溶体进行价电子结构分析,并计算各键键能。结果表明：Mg微合金化改变了Mo原子和Si原子的杂化状态,从而使相应的价电子结构参数发生变化。Mg微合金化之后,最强键上共价电子对数和键能降低,表明固溶体的熔点和硬度降低。共价电子数在总价电子数中所占比例下降,晶格电子数增加,因而Mg微合金化之后宏观上表现为材料的强度降低,但是塑性和导电性增加,脆性降低。
Based on the empirical electron theory（EET） of solids and molecules,the valence electron structure of Mo（Si0.95,Mg0.05）2 solid solution was studied and compared with that of pure MoSi2to investigate the effect of microalloying with magnesium（Mg） on the properties of molybdenum disilicide（MoSi2）.The bond length difference（BLD） method and the average atom model in substitution solid solutions were employed in these analyses.The results show that the hybridization states of Mo and Si atoms are altered by alloying Mg into MoSi2,and correspondingly,the parameters of valence electron structure are changed.After magnesium-microalloying,the covalent electron amount and the bond energy on the strongest bond drop,implying that the melting point and hardness decrease.Furthermore,it can be concluded that the proportion of covalent electrons in total valence electrons reduces while the lattice electrons increase,which will lead to the reduction in strength and brittleness,and increase in plasticity and conductivity of Mo（Si0.95,Mg0.05）2 solid solution.
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