合金元素在NbC/fcc-Fe界面的偏析行为和硼的影响  

Segregation Behavior of Alloying Elements at NbC/fcc-Fe Interface and Effects of Boron

作　　者：杨静 张翊[1] 董楠 李花兵[2] 韩培德[1] 姜周华[2] Yang Jing;Zhang Yi;Dong Nan;Li Huabing;Han Peide;Jiang Zhouhua(College of Material Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;School of Metallurgy,Northeastern University,Shenyang 110004,China)

机构地区：[1]太原理工大学材料科学与工程学院,山西太原030024 [2]东北大学冶金学院,辽宁沈阳110004

出　　处：《稀有金属材料与工程》2022年第6期2056-2062,共7页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China(U1860204,51871159);Natural Science Foundation of Shanxi Province(201801D221125)。

摘　　要：基于密度泛函理论(DFT)的第一性原理方法,研究了Si、Ni、Mn、Cr、Mo在NbC/fcc-Fe界面的偏析行为,以及B对合金元素界面偏析行为的影响。结果表明,Cr和Mo可以稳定存在于界面和NbC中;Mo更倾向于在界面和NbC中偏析;Ni和Mn在界面上有轻微的偏析倾向。另外,Mo容易偏析到NbC中形成复合碳化物。当Mo/Nb含量比小于2/3时,(Nb,Mo)C复合碳化物更稳定,结合能更大,这应该与Mo和C、Fe之间的强电子相互作用有关。当B掺杂到界面时,Mo和Cr向界面偏析的趋势被抑制。特别是B抑制了界面处Mo的偏析,从而提高了材料的耐蚀性。此外,B可使Ni、Mn趋于均匀分布在基体中。Based on the first-principles method of density functional theory(DFT),the segregation behavior of Si,Ni,Mn,Cr,and Mo at the NbC/fcc-Fe interface was studied,and the influence of B on the segregation behavior of alloying elements was analyzed.The results show that Cr and Mo can stably exist in the interface and NbC.Mo tends to segregate in the interface and NbC;Ni and Mn have a slight tendency to interface segregation.Mo is easy to segregate into NbC to form composite carbides.When the Mo/Nb content ratio is less than 2/3,the(Nb,Mo)C composite carbide is more stable and the binding energy is greater,which should be related to the strong electronic interaction between Mo and C and between Mo and Fe.When B is doped to the interface,the tendency of Mo and Cr to segregate to the interface is suppressed,expecially the segregation of Mo at the interface,thereby improving the corrosion resistance of the material.In addition,B can make Ni and Mn tend to be uniformly distributed in the matrix.

关 键 词：合金元素 偏析能 NbC/fcc-Fe界面 硼 第一性原理 

分 类 号：TG142.71[一般工业技术—材料科学与工程]