Ni晶界上金属和非金属元素的相互作用  

Interaction between metallic and nonmetallic elements on grain boundary of nickel

作　　者：方淑娟 石松鑫 祝令刚[1] 周健[1] FANG Shujuan, SHI Songxin, ZHU Linggang , ZHOU Jian(School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, Chin)

机构地区：[1]北京航空航天大学材料科学与工程学院,北京100083

出　　处：《北京航空航天大学学报》2018年第4期862-867,共6页Journal of Beijing University of Aeronautics and Astronautics

基　　金：国家自然科学基金(51401009;51571008)~~

摘　　要：采用基于密度泛函理论的第一性原理计算方法,研究了常用合金化元素与非金属元素在晶界(GB)的偏析及其相互作用。选取2种类型的晶界结构进行研究:密排的晶界和较疏松的晶界。溶解能计算表明,金属和非金属元素在Σ5晶界上均有明显的偏析行为,而在Σ3晶界上的偏析现象不明显。通过计算常用过渡族合金化元素与非金属杂质C、H、O、N、B在各自最稳定位置的相互作用能,发现Ru、Re、W和Ta对O有强烈的排斥作用,因此对晶界抗氧化有益处;Ta排斥H,有抗晶界氢脆的效果。通过对金属元素与非金属元素在晶界上相互作用的系统研究,为Ni合金的晶界工程提供有价值的参考。First-principles calculations based on density functional theory are used to study the segregation of metallic and nonmetallic elements as well as their interactions on the grain boundary（GB） of nickel.Two typical GBs are constructed： close-packed GB and quite open GB. According to the solution energy calculation,both the metallic and nonmetallic elements show strong segregation behavior on the Σ5 GB,while for the Σ3 GB,the segregation is not so significant. The interaction energies between the common transition alloying elements and nonmetallic elements C,H,O,N and B are calculated when they occupy the most energy-favorable positions. It is found that Ru,Re,W and Ta exhibit strong repulsion to O,indicating beneficial effects for the oxidation resistance behavior; Ta shows strong repulsive interaction to H,which should be helpful for the inhibition of the hydrogen-embrittlement. The present work is useful for the grain boundary engineering of Ni-based superalloy by systematically studying the interaction between metallic and nonmetallic elements at grain boundaries.

关 键 词：晶界(GB)偏析 镍基高温合金 氢脆 点缺陷 第一性原理计算 

分 类 号：V252.2[一般工业技术—材料科学与工程] O483[航空宇航科学与技术—航空宇航制造工程]