Al-Cu-Mg-Ag合金Ω/Mg-Ag/α界面价电子结构分析

Valence electron structure analysis of the interface between W/Mg-Ag/a in Al-Cu-Mg-Ag alloy

摘要:

基于EET理论,研究了W相与基体α之间界面的原子结构,计算了a、Mg-Ag偏聚区、W相空间价电子结构和W/Mg-Ag/a界面、W//a界面的价电子结构,分析了W/Mg-Ag/a界面价电子结构与界面性能的关系。研究表明：Ω/Mg-Ag/α界面外层Mg-Ag/α面电子密度差为16.54%,内层Ω/Mg-Ag面电子密度差为50.73%,外层的连续性好于内层；Mg-Ag层使W相与基体α间的界面电子密度差减小1.13%,使(111)_α面上的最强共价键键合力增大14.52%、(111)_α面的共价电子密度增大146.87%、(001)_Ω面最强共价键键合力增大45.85%、(001)_Ω面的共价电子密度增大了45.30%。Mg-Ag层增大了W相对位错滑移的阻力,减小界面两侧相平面的电子密度差,增加了界面连续性,减小了界面应力,增大了界面结合力,增大了界面稳定性,提高了合金的强韧性。

Abstract:

Based on the empirical electron theory of solids and molecules, the VESs of the matrix a, Mg-Ag segregation area, W phase and the interfaces of W/Mg-Ag/a, W//a were calculated after studying the interface atom structure between the matrix a and W phase, then the relationship between the interface VESs W/Mg-Ag/a and the interface properties was analyzed in Al-Cu-Mg-Ag alloy in this paper. The results show that the continuity of the outer of W/Mg-Ag/a is better than that of the inner because that the electron density difference of Mg-Ag/a is 16.54% and that of W/Mg-Ag is 50.73%. The Mg-Ag layer makes the interface electron density difference of W/a decrease by 1.13%, while it makes the strongest covalence band force and the covalence electron density in (111)a increase by 14.52% and 146.87% respectively, it also makes the strongest covalence band force and the covalence electron density in (111)W increase by 45.85% and 45.30% respectively. The existence of Mg-Ag layer enhances the alloy strength and toughness owing to it increasing the obstruction of W phase to the dislocation, the interface continuity, the interface binding force and stability while it decreasing the interface electron density differences and the interface stress.