Zr对Al-Li合金晶粒细化作用的电子理论分析

Valence Electron Structures of Al-Li Alloy with Minor Zr and Its Effect on Grain Refinement

运用固体经验电子理论(EET),对Al-Li-Zr合金的价电子结构进行计算。结果表明:Zr与Al原子存在强烈的相互作用,在固溶体中形成Al-Zr偏聚区。Al-Zr原子的偏聚析出的细小Al3Zr粒子,均匀弥散分布在基体中,起到抑制晶粒长大,细化Al3Li晶粒的作用。Al3Zr和Al3(Zr,Li)粒子具有较强的Al-Zr共价键,不易被位错的切割折断,因而对位错的运动有较大的阻力,对合金起到强化作用。另一方面,共格复合相Al3(Zr,Li)的析出,可以降低共格界面错配度,使得界面键合强度分布较均匀,对提高基体的韧性是有益的。

The valence electron structures of Al-Li with minor Zr were calculated according to the 'Empirical Electronic Theory in Solid and Molecules'(EET).The result show that the interations of Al with Zr atoms,which lead to form the Al-Zr segregation regions,promotes the precipitations of Al_3Zr particles and produces a remarkable refinement in the grain size of alloys.