First-principle investigation of the structural stability and electronic property of precipitates on the Cu-rich side of Cu-Ni-Si alloys

The energetic and electronic structures of precipitates on the Cu-rich side of Cu-Ni-Si alloys were investigated by using the first-principle calculations based on plane-wave pseudopotential method. The negative formation heats and the cohesive energies of these precipitates were estimated with electronic structure calculations, and their structural stability was also analyzed. The results show that δ-Ni₂Si, γ-Ni₅Si₂ and β-Ni₃Si precipitates all have great alloying ability and structural stability, which, after comparing their density of states (DOS), is found attributed to the pseudogap effect near the Fermi level (E _F) and strong hybridization between the Ni-3d and Si-3p states. Compared with the other two precipitates, the δ-Ni₂Si precipitate has the greatest structural stability, which is resulted from its lower DOS at E _F and the main bonding peaks slightly moving to the low energy region.     

大秦线2亿t重载扩能改造工程线路及轨道设计标准浅析

通过大秦线2亿t重载扩能改造工程,分析线路平、纵 断面和轨道结构的关系,提出重载铁路存在的问题和解决措施 或建议,结合大秦线现状及扩能线路轨道标准提出需要进一步 研究的问题。