【作者】 刘慧；

【导师】 高英俊；

【作者基本信息】 广西大学 ， 理论物理， 2003， 硕士

【摘要】 本文运用固体与分子经验电子理论（简称EET理论），对Al-Li-Cu系合金相空间和相界面的价电子结构进行计算。主要集中在如下几方面： 1．建立 Al-Li-Cu系合金固溶体中存在各相的价电子结构模型，认为固溶体内包含了四类晶胞：α-Al晶胞，Al-Li晶胞，Al-Cu晶胞和Al-Li-Cu晶胞。并计算了这四类晶胞的价电子结构。 2．对Al-Li-Cu系合金的过饱和固溶体在时效过程中脱溶的二元析出相δ′相（Al₃Li）、θ＂相、θ′（Al₂Cu）相和θ（Al₂Cu）相，以及三元析出相T₁（Al₂CuLi） 相的价电子结构进行计算。 3．对Al-Li-Cu系合金的基体α-Al与析出相界面，如α-Al／δ′（Al₃Li）界面、α-Al／θ＂界面、α-Al／θ′（Al₂Cu）界面、α-Al／θ（Al₂Cu）界面、α-Al／T₁（Al₂CuLi） 界面的面电荷密度进行计算。 研究结果表明： 在Al-Li-Cu系合金的固溶体中，Al原子和Li、Cu原子之间存在强烈的相互作用，容易形成Al-Li、Al-Cu、Al-Li-Cu 偏聚区。这些细小偏聚区分散在固溶体中，有效地抑制着基体 Al晶粒的长大，起到了固溶强化的作用。 Al-Li-Cu系合金在时效过程中的二元析出相δ′（Al₃Li）、θ＂相、θ′相 广西大学硕士学位论文（AI，Cll）和 O相（AI，Cll），以及三元析出相 TI相（AI，CULi）的界面与基体AI界面电子密度的连续，对合金起到了时效强化和析出强化的作用。更多还原

【Abstract】 The valence electron structures of maid phases and phase interphase boundaries in Al-Li-Cu based alloy were analyzed according to the Empirical Electronic Theory in solid and molecules (EET). The following aspects are included in this thesis:1. The models of valence electron structure of maid phases in Al-Li-Cu based alloy were established. The solid solution of Al-Li-Cu based alloy was contained four cells: a-Al cell, Al-Li cell, Al-Cu cell and Al-Li-Cu cell. The valence electron structures of above cells were calculated.2. The valence electron structures of the precipitations of Al-Li-Cu based alloy in early aging, such as d (Al3Li),0",0’(Al2Cu), 0(Al2Cu) and Ti(Al2CuLi), were calculated.3. The valence electron structures of phase interphase boundaries between the matrix and the cells above, the matrix and the precipitations were calculated.The results show that:The strong interaction of Al with Li and Cu in solid solution of Al-Li-Cu based alloy, which lead to the behavior of Al-Li segregation, Al-Cu segregation and Al-Li-Cu segregation. The strong segregations are restrained the growth of the matrix, and the strengthening of the alloy was promoted.On the interphase boundaries between the matrix and the precipitates, electronic density is continued in Al-Li-Cu based alloy. The functions of aging hardening and precipitation hardening are remarkable in the alloy.更多还原