(1. 湖南大学 材料科学与工程学院,长沙 410082;2. 长沙航空职业技术学院 航空装备工程系,长沙 410124)
摘 要: 采用第一原理赝势平面波方法计算了Ru合金化前后g -Ni/g ′-Ni3Al相界的电子与能态结构,并比较强化元素Ru分别占据不同亚点阵位时对相界断裂强度的影响。结果表明:Ru置换Ni/Ni3Al 相界区域中的Ni或Al原子,都可明显提高Ni/Ni3Al相界的断裂强度;尤其以Ru置换g -Ni/g ′-Ni3Al相界界面层的Al原子时,对相界的强化效果最好。电子态密度与电子密度分布图的分析结果显示:Ru合金化对g -Ni/g ′-Ni3Al相界的强化可归因于Ru与其最近邻Ni原子间强烈的电子相互作用引起的相界区域层间原子价键强度的增强。
关键字: -Ni/ -Ni3Al相界;合金化效应;第一原理计算;断裂功
(1. School of Materials Science and Engineering, Hunan University, Changsha 410082, China;2. Department of Aeronautical Equipment Engineering, Changsha Aeronautical Vocational and Technical College,Changsha 410124, China)
Abstract:Using the first principles plane-wave pseudopotential method, the energetic and electronic structure of Ni/Ni3Al interface with Ru addition were calculated. The Griffith rupture works W of Ni/Ni3Al interface with Ru addition demonstrate that the substitution of Ru atom for either Ni atom or Al atom is profitable to improve the rupture strength of the interface. Among which the replacement of Ru for Al at the Ni/Ni3Al interfacial layer is the best. The analysis of electron densities of states (DOS) and the distributions of valence electron densities of Ni/Ni3Al interface reveal that the electronic interaction between the first nearest neighbor (FNN) Ru-Ni atoms is stronger than that between FNN Ni-Al atoms, and the overlapping electron numbers within the interlayer on the Ni/Ni3Al interface with Ru addition increase, compared with the interface without Ru addition. The strengthening effect of Ru on the rupture strength of -Ni/ ′-Ni3Al interface can be attributed to the enhancement of the interlayer bonding, which is induced by the strong interaction between the Ru-Ni atoms.
Key words: -Ni/ -Ni3Al interface; alloying effect; first-principle calculation; rupture work