Mg17Al12相电子结构计算与键络分析

基于EET理论，计算了Mg-Al系合金中主要的强化相γ-Mg17Al12的价电子结构，分析了其键络空间分布。Mg17Al12空间键络由Al-Al原子集团主键络、Al-MgⅢ次键络和Al-MgⅡ、Al-MgⅠ弱键络及MgⅡ-MgⅢ层状键络组成，其中Al-MgⅢ原于形成的弱键G是整个键络的薄弱环节。Mg17Al12晶内、晶界弥散析出，钉扎位错运动，阻碍品界滑移传递的强化作用主要依靠Al-Al原子集团主键络。通过合金化增强Mg17Al12弱键G是改善其热稳定性，提高Mg-Al基合金工作温度的有效途径。

Bond Network Analysis and Calculation of Valence Electron Structure of Mg17Al2 Phase

The valence electron structure and the space distribution of covalent bond of the main strengthening phase Mg17Al12 in magnesium aluminum alloy were calculated,based on EET theory.The space bond branch of Mg17Al12 was composed of the main bond branch of the Al-Al atomic group,the Al-MgIII secondary bond branch,the Al-MgII and Al-MgI weak bond branch and the MgII-MgIII laminar bong branch after analyzing,hereinto the weak bond G which was composed of the Al-MgIII atom,was the bottleneck of the whole space bond branch.It was the Mg17Al12 diffusing precipitated on the intra crystalline and the crystal boundary that anchored the movement of the dislocation and hindered the slipping of the crystal boundary.This kind of the strengthening effect mainly depended on the main bond branch of Al-Al atomic group.To enhance the weak bond G by the method of alloying was an effective path to improve the thermal stability and enhance the working temperature of the Mg-Al alloy.