Mg-Zr合金固溶体的价电子结构分析

发布时间：2018-05-11 18:16

本文选题：Mg-Zr合金 + 固溶强化　；参考：《稀有金属》2015年11期

【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)=16.5541Δρ'~(Mg-Zr/Mg-Zr)=3.8673Δρ'~(Mg/Mg)=0,相应的的原子状态组数σ_(Mg-Zr/Mg-Zr)=45σ_(Mg/Mg-Zr)=9σ_(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。
[Abstract]:Based on the empirical electron theory of solid and molecular, the valence electron structure of Mg-Zr alloy solid solution was analyzed. The valence electron structure parameters (VESPs), which characterize the mechanical properties of the alloy, are calculated. The logarithmic statistics of the shared electrons on the strongest covalent bonds are calculated. The number of atomic state groups (蟽 N), the statistical values of the covalent electron density difference (螖蟻) and the phase interface in the unit cell are calculated. The number of possible atomic state groups (蟽). The results show that the common logarithmic statistical value of electron logarithm is 0.12984, which is obviously higher than that in pure mg 0.10991g. The relationship between the statistical values of covalent electron density at the interface of each phase in the alloy solid solution is as follows: 螖蟻 / Mg-ZrN 16.5541 螖蟻 / Mg-Zr / Mg-ZrN 3.8673 螖蟻 = 3.8673 螖蟻 ~ (-1), the corresponding atomic state group 蟽 Mg-ZrR / Mg-Zr ~ (2 +) 45 蟽 / mg / Zr ~ (9) 蟽 / mg / mg ~ (-1); the increase of 螖蟻'Zr value indicates that the addition of alloying elements increases the stress of the interface and increases the dislocation density of the matrix. Therefore, the interface and matrix were strengthened, and the increase of 蟽 value indicated that the dissolution of Zr promoted the continuity of electron density at the interface of Zr-containing crystal cell in alloy solid solution, which led to the enhancement of the mobility of the dislocation and the improvement of the plasticity of the alloy. The sensitivity of stress corrosion is reduced. The alloy element Zr increases the value of nna A, 螖蟻 'and 蟽 of Mg-Zr alloy solid solution, which is the result of the comprehensive effect of solid solution strengthening and interface strengthening.
【作者单位】：辽宁石油化工大学机械工程学院;东北大学材料电磁过程研究教育部重点实验室;辽宁石油化工大学顺华能源学院;
【基金】：国家自然科学基金项目(51201029,51204053)资助
【分类号】：TG146.22

【参考文献】