Ni对bcc-Fe/ε-Cu界面影响的第一性原理研究  

First-Principles Study of bcc-Fe/ε-Cu Interface with Different Ni Contents

作　　者：王海燕[1,2] 高雪云[1,3] 任慧平[1,2] 李德超[1,2] 刘宗昌[1] 

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010 [2]内蒙古白云鄂博矿多金属资源综合利用重点实验室,内蒙古包头014010 [3]中冶东方工程技术有限公司长材事业部,内蒙古包头014010

出　　处：《稀有金属》2016年第1期92-96,共5页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(50361001)资助

摘　　要：采用基于密度泛函理论(DFT)的第一性原理,研究了Ni对bcc-Fe/ε-Cu界面结合的影响。建立了ε-Cu在bcc-Fe的析出模型,选取界面两侧不同阵点位置,计算Ni在不同位置的偏聚能,分析了Ni在界面区域的占位倾向,在此基础上探究了Ni对bcc-Fe/ε-Cu界面结合的影响。利用Rice-Wang热力学模型的计算表明,当Ni原子处于偏聚能最低的位置时,能够强化界面的结合。而界面分离功计算结果显示,Ni偏聚于bcc-Fe/ε-Cu界面后,界面分离功由279.8 m J·m^(-2)增加到286.7 m J·m^(-2),表明Ni偏聚后会使界面体系更加稳定。Ni偏聚于界面后对界面区域的电子结构也产生一定影响,差分电荷密度显示,与纯bcc-Fe/ε-Cu界面相比,Ni偏聚后会在其周围聚集较多的电子,且Ni与相邻原子之间电子云方向性更为明显;同时,Ni也使近邻Cu和Fe原子的态密度(DOS)向成键态偏移,这使得Ni偏聚加强了bcc-Fe/ε-Cu界面的结合,使界面区更为稳定。The influence of Ni on the bcc-Fe/ε-Cu interface was investigated by means of first-principles calculations based on the density functional theory （DFT）. To identify the most preferred energetic site for Ni atom, the atom model of ε-Cu precipitation in bcc- Fe was built, the segregation energies of Ni atom at different sites of bcc-Fe/ε-Cu interface was calculated, and the effect of Ni on the interracial binding was discussed as well. From the calculations based on Rice-Wang model, it could be found that Ni atom induced en- hancement effect on the interface when in the lowest segregation energy state. And the work of adhesion of the interface with Ni segrega- tion was 286.7 mJ.m-2, higher than the Ni free one that was 279.8 mJ.m-2, which indicated that Ni segregation made the interface system more stable. The result of the calculated electronic structure showed that when Ni segregated at the bcc-Fe/ε-Cu interface, the electrons around Ni increased, and the orientation of electron clouds between Ni and its neighboring atoms was enhanced ; at the meantime, the density of atoms （DOS） of Cu and Fe atom near the Ni atom moved to the bond state somewhat, which made the interface more stable.

关 键 词：NI bcc—Fe CU 第一性原理 

分 类 号：TG142.1[一般工业技术—材料科学与工程]