Al-Cu-Mg-Ag合金Ω/Mg-Ag/α界面价电子结构分析

Analysis of Valence Electron Structure of the Interface Between Ω/Mg-Ag/α in Al-Cu-Mg-Ag Alloy

基于EET理论,研究了Al-Cu-Mg-Ag合金Ω相与基体α之间界面的价电子结构,计算了α、Mg-Ag偏聚区、Ω相空间价电子结构和Ω/Mg-Ag/a界面、Ω/α界面的价电子结构,分析了Ω/Mg-Ag/α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。

Based on the empirical electron theory of solids and molecules,the valence electron structures of the matrix a,Mg-Ag segregation area,Ωphase and the interfaces ofΩ/Mg-Ag/α,Ω/αwere calculated after studying the interface valence electron structure between the matrix a and W phase.Then the relationship between the interface valence electron structures of W/Mg-Ag/a and the interface properties in Al-Cu-Mg-Ag alloy was analyzed.The results show that the continuity of the outer ofΩ/Mg-Ag/αis better than that of the inner because the electron density difference of Mg-Ag/a is 16.54%and that ofΩ/Mg-Ag is 50.73%.The Mg-Ag layer makes the interface electron density difference ofΩ/αdecrease by 1.13%,while it makes the strongest covalence bond force and the covalence electron density in(111)αincrease by 14.52%and 146.87%,respectively.It also makes the strongest covalence bond force and the covalence electron density in(111)Ωincrease by 45.85%and 45.30%,respectively.The existence of Mg-Ag layer enhances the alloy strength and toughness because it increases the obstruction ofΩphase to the dislocation,the interface continuity,the interface bonding force and stability while it decreases the interface electron density differences and the interface stress.