Al-4.5Mg-Zr-Er合金的电子理论研究

Electron Theory Research on Al-4.5Mg-Zr-Er Alloys

以Miedema二元合金生成热模型为基础,结合George Kaptay提出的组元间相互作用参数表达式,计算了Mg、Zr、Er与Al之间随温度变化的相互作用参数;同时运用固体与分子经验电子理论(EET),计算了Al-4.5Mg-Zr-Er合金的价电子结构。根据计算结果和电镜研究综合认为,合金溶体中Zr、Er与Al原子之间存在强烈的交互作用,可以形成Al-Zr、Al-Er、Al-Zr-Er晶胞的偏聚区。随着凝固温度的降低,在界面前沿Al-Zr-Er原子会强烈偏聚形成Al3Er相,并可能形成Al3(ZrxEr1-x)复合相粒子作为异质形核的核心,对基体的晶粒起到强烈的细化作用,以提高铝镁合金的机械性能。

Interaction parameter LA-B between components proposed by George Kaptay is introduced, then the interaction parameters between Al and Er, Zr, Mg are worked out based on Miedema model. Valence electron structures of Al-4.5Mg-Zr-Er alloys are also calculated by empirical electron theory（EET） in solid. According to calculated results and microscope observation, there exists strong interaction among Al,Zr and Er in the alloy solution, naturally from segregation region of Al-Zr, Al-Er and Al-Zr-Er cells. As the temperature decreases during the solidification process, in the interface Al3 Er and the possible Al3 （Zrx Er1-x） particles are formed by the strong segregation of Al-Zr- Er atoms, which act as heterogeneous nuclear that are firstly crystallized in alloy to make grains refine remarkably, and improve the mechanical properties of Al-Mg alloys.