A review of composition evolution in Ni-based single crystal superalloys

Wanshun Xia¹，Xinbao Zhao¹，Liang Yue¹，Ze Zhang²

1. Institute of Superalloys Science and Technology, School of Materials Science and Engineering, Zhejiang University2. Center of Electron Miscroscopy, Zhejiang University

摘 要：Due to the outstanding creep performance, nickel-based single crystal superalloys（Ni-SXs） are extensively applied in modern aero-engine and industrial gas turbine. Apart from the special single crystal structure which is disadvantageous to extension of creep cracks, Ni-SXs derive the creep strength from intrinsic two-phase microstructure（γ phase and γ’ phase）. Main microstructural parameters including volume fraction of γ’ phase and the lattice misfit, and the formation and distribution of precipitated phase are determined by the compositions of alloys. Besides, the creep properties are greatly influenced by these microstructural parameters and precipitated phase. This review has summarized the relationships between different alloying elements and microstructures and indicated their influence on creep properties of Ni-SXs. In addition, with the improvements of experimental methods and characterization technique, some recent discoveries have provided additional evidence to support or challenge the pervious creep theories of superalloys. In view of these new discoveries, this review has provided some perspectives which can be referenced in future compositional design of Ni-SXs.

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