中文摘要：

基于固体与分子经验电子理论（EET）,分析了Mg-Zr合金固溶体的价电子结构,计算了表征合金力学性能的价电子结构参数（VESP）最强共价键上共用电子对数统计值（n＇A）,晶胞中可能存在的原子状态组数（σN）,相界面上共价电子密度差统计值（Δρ＇）及相界面中可能存在的原子状态组数（σ）。结果表明：Mg-Zr合金固溶体晶胞的最强共价键上共用电子对数统计值（n＇_A~（Mg-Zr））值为0.12984,明显大于纯Mg中对应的数值（0.10991）,相应的原子状态组数σ_N~（Mg-Zr）（9）〉σ_N~（Mg）（1）,表明Zr元素固溶产生了显著的固溶强化效果。而合金固溶体中各相界面上共价电子密度差统计值的关系为Δρ＇~（Mg/Mg-Zr）=16.5541〉Δρ＇~（Mg-Zr/Mg-Zr）=3.8673〉Δρ＇~（Mg/Mg）=0,相应的的原子状态组数σ_（Mg-Zr/Mg-Zr）=45〉σ_（Mg/Mg-Zr）=9〉σ_（Mg/Mg）=1;Δρ＇值的增大,说明合金元素Zr的加入提高了基体界面的应力,使该处的位错密度增加,因此界面和基体被强化了;而σ值的增多,表明Zr的溶入促使合金固溶体中含Zr晶胞界面上的电子密度连续性增强,导致错位的运动能力增强,使合金的塑性提高,降低了应力腐蚀敏感性。合金元素Zr使Mg-Zr合金固溶体的n＇A值增大,Δρ＇值提高,σ值上升,是固溶强化和界面强化综合作用的结果。

英文摘要：

Based on empirical electron theory of solids and molecules （ EET）, valence electron structure of Mg-Zr alloy solid solution was analyzed, and the statistical value of shared electron pair number of the strongest covalent bond （n＇A ） , the group number of the possible atom state in cell （ten）, the statistical of covalent electron density differences at different types of phase interface （Δρ＇） and the group number of the possible atom state in the phase interface （σ） which characterized the mechanical properties of Mg-Zr alloy t Mg-Zr were calculated. The results showed that the statistical value of shared electron pair number of the strongest covalent bond （n＇Mg-Zr A ） of Mg-Zr solid solution was 0. 12984, which was significantly greater than that of pure Mg （0. 10991 ）. Moreover, the corresponding Mg-Zr Mg group number of atom state σ Mg-Zr N （9） 〉 σ Mg N （ 1 ）, thus indicating that the solution of Zr element produced a significant solid solution strengthening effect. And the relationship among the statistical value of covalent electron density differences at different types of phase interface in the alloy was that Δρ＇＇Mg/Mg-Zr = 16. 5541 〉 Δρ＇Mg-Zr/Mg-Zr = 3. 8673 〉 Δρ＇Mg/Mg = 0, while the corresponding group number of sets of the atom state was as follows： σMg-Zr/Mg-Zr = 45 〉 σMg/Mg-Zr = 9 〉 σMg/Mg = 1 ; the increase of Δρ＇ value indicated that the addition of alloying elements Zr improved the interface stress and increased the dislocation density ; as a result, both of the phase interface and matrix were strengthened; while the increase of te value indicated that the solution of Zr into matrix promoted the continuity of electron density at the interface of Zr contained unit cell, enhanced the mobility of dislocation, improved the ductility of alloy and reduced the stress corrosion sensitivity. The alloy element Zr increased the value of n＇A, Δρ＇ and cr of Mg-Zr alloy, which could be attributed to the solution strengthening