(广西大学 物理科学与工程技术学院，南宁 530004)
摘 要: 应用基于价键理论和能带理论建立的固体与分子经验电子理论(EET)和改进的界面TFD理论，将合金宏观性能的研究追溯到原子成键的电子结构层次，并对Al-Mg-Si合金的序列析出相内部原子间的价电子成键及其与基体界面间形成的界面键络特征研究进行总结，比较各析出相的键强、结合能以及析出相与基体的界面能。结果表明：β″相对合金的强化作用最显著，pre-β″相的次之；结合能与最强键键能的变化也能反映熔点的变化， pre-β″相、β″相与U1相的熔点比基体和其他GP区的熔点高；各析出相的键强演变规律与实验强化曲线的变化规律相符。
关键字: Al-Mg-Si合金；析出相；原子成键；界面
（School of Physics Science and Engineering, Guangxi University, Nanning 530004, China）
Abstract:The macro-property of the alloy was gone back to the electronic scale of atomic bonding by using the empirical electronic theory (EET) in solid and molecule and the improved interface TFD theory established based on bond theory and band theory. The investigation of interface bonding feature of the atomic bonding of sequence phase and the atomic bonding at the interface between the matrix and the precipitate in Al-Mg-Si alloy was systematically summed through comparing the bond strength, cohesive energy, interface energy between the precipitate and the matrix. The results show that the most effect of strengthening for the alloy is owing to the β″ phase, the second is the pre-β″ phase; the variation of the cohesive energy and the strongest bond energy can also show the melting point of the alloy, which indicates that the melting points of pre-β″ phase, β″ phase and U1 phase are higher than those of GPZ phases and the matrix. The calculated results of atomic bond strength evolution of precipitates are in good agreement with the experiment results of the strengthening alloy.
Key words: Al-Mg-Si alloy; precipitate; atomic bonding; interface
