材料期刊网

    利用结构能和原子轨道自能差定义了原子的结合能和结合能差,并用递归法计算了ZA27合金中重位密度分别为1/5和1/9的α相大角度重位点阵晶界的电子结构.结果表明：重位密度越大，晶界结构能越低,从而越稳定.Fe,Y与晶界结合牢固，强化晶界，而Pb与晶界结合弱，降低晶界强度.合金元素或杂质容易偏聚在低重位密度晶界-即高指数晶界.重位密度大的晶界费米能级低于重位密度小的晶界，偏聚在晶界的杂质原子可以改变晶界的费米能级，影响晶界的电位， 进而影响合金的腐蚀性能.

    The binding energy and the difference of the binding energies of an atom were defined with the difference of the structure energy and atom orbital self-energy.Recursion method was adopted to calculate the electronic structure of the high angle gain boundaries of  phases with coincidence-site density of 1/5 and 1/9 in ZA27 alloy.The results show that:the greater the density of coincidence-site is,the lower the structure energy of grain boundary is,thereby,the grain boundary with large density of coincidencesite is more stable.Fe and Y bond strongly with the grain boundary,so they strengthen the grain boundary.But Pb bonds weakly with grain boundary,leading to the weak bond strength of the grain boundary.Alloying elements and impurities are easy to segregate to the grain boundary with low density of coincidence-sitegrain boundaryplanes with high indices.The Fermi energy of grain boundary with high coincidence-site density is lower than that of the grain boundary with low coincidence-site density.The impurity atoms segregated on the grain boundary can change the Fermi level of grain boundary,which has influence on the electronic potential of grain boundary,then the corrosion performance of ZA27 alloys is affected.