Re与Ru合金化对Ni/Ni3Al相界电子结构影响的第一原理研究

采用第一原理赝势平面波方法研究了Re与Ru合金化前γ-Ni/γ'-Ni3Al相界的电子与能态结构.断裂功计算结果显示:Re置换γ-Ni相区中的Ni或Ru置换γ'-Ni3Al相区中的Al,均可提高Ni/Ni3Al相界的断裂强度;Re与Ru在相界区复合合金化时,当Re与Ru分别占据共格(002)γ/γ'原子层邻近(001)γ原子层上的Ni原子位与(001)γ'原子层上的Al原子位时,γ-Ni/γ'-Ni3Al相界的断裂强度可进一步提高,若其中的Ru置换γ'-Ni3Al相区内层Al,刚复合合金化Ni/Ni3Al相界的断裂强度不仅没有提高,反而比Ru单独合金化时Ni/Ni3Al相界的断裂强度还低.电子态密度与电子密度分布图的分析表明:Re与Ru合金化对γ-Ni/γ'-Ni3Al相界断裂强度的影响可归因于Re和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成键相互作用的改变.

A first-principles study on properties of Ni/Ni3Al interfaces with Re and Ru addition

Energetics and electronic structures of Ni/Ni3Al interface with additions of Re and Ru have been investigated by a first-principles plane-wave pseudopotential method. The calculated rupture works W show both of that either Re substitutes for Ni in g-Ni block or Ru replaces for Al atoms in g¢-Ni3Al block are profitable to improve the strength of the Ni/Ni3Al interface. In the case of the multiple alloying of Re and Ru, it is found only the mode of Re and Ru, respectively, occupying at Ni and Al sites at (001) atomic layers adjacent to the coherent (002) interfacial atomic layer can further enhance the Ni/Ni3Al interface. While Ru locates at Al sites in g¢-Ni3Al block and far away from the coherent (002) interfacial layer, it is found the multiple alloying of Re and Ru not only do not elevate the strengths of Ni/Ni3Al interface with addition of Re or Ru but make them decrease to a lower value than that of clear Ni/Ni3Al interface without addition as well. A deep analysis of electron densities of states (DOS) and the distributions of valence electron densities of Ni/Ni3Al interface before and after alloying reveals that the effect of Re and Ru alloying on the rupture strength of g-Ni/g¢-Ni3Al interface can be attributed to the change of the interlayer bonding in the interfacial region induced by strong electron interactions within first nearest neighbor (FNN) Re-Ni and Ru-Ni atoms, respectively, compared with FNN Ni-Ni and Ni-Al.