稀土对ZA27合金晶间腐蚀影响的电子理论研究  

Electronic Theory Study on the Influence of Rare Earth Elements on the Intergranular Corrosion of ZA27 Alloys

作　　者：刘贵立[1] 李荣德[1] 郭玉福[1] 

机构地区：[1]沈阳工业大学材料科学与工程学院,沈阳110023

出　　处：《化学学报》2006年第16期1631-1634,共4页Acta Chimica Sinica

基　　金：国家自然科学基金(No.50571071);辽宁省教育厅科学研究计划(No.05L297);沈阳市科技计划基金(No.1041020-1-04-6)资助项目.

摘　　要：通过自行开发的计算机软件构造了ZA27合金中α相大角度晶界析出η相及稀土元素的原子集团模型.采用递归法计算了Al,Zn,La,Y的局域态密度,计算并分析了α相、η相的总态密度和费米能级,及稀土对态密度和费米能级的影响.计算表明:稀土元素的局域态密度形状与Zn相近,其与Zn结合的能力大;稀土元素降低η相的费米能级,减小Zn,Al电极电位差,具有抑制晶间腐蚀的作用;稀土元素不改变α相、η相的总态密度形状,但使η相的态密度增大,改变η相的电子结构;晶格结构对原子的态密度有一定的影响,掺杂原子的态密度趋于与基体原子态密度相同.The atomic cluster model of a phase of ZA27 high angle grain boundary including rare earth elements （La, Y） and η　phase was constructed by self-developed computer programm. Recursion method was used to calculate the local density of states of A1, Zn, La and Y elements, and the total density of states and Fermi level of α phase and η　phase. The influence of rare earth elements （La, Y） on the density of states and Fermi level was discussed. The calculated results show that： the local density of states of RE element are similar to that of Zn, so RE element can combine with Zn easily; RE element can reduce the Fermi level of η phase, lower the difference of electrode-potential between Zn and A1, so RE element is of the function to restrain the intergranular corrosion of zinc-aluminum alloys; RE element can not change the shape of total density of state of α and η　phase, but can heighten the total density of state of η　phase, and change the electronic structure of η　phase; the crystal structure have effect on the atomic density of states, the density of state of impurity atom tends to be similar with that of matrix atom.

关 键 词：稀土 晶界 晶间腐蚀 电子结构 

分 类 号：O646.6[理学—物理化学]