Microstructures and Creep Behavior of a Directionally Solidified NiAl-Fe（Nb） Multiphase Intermetallic Alloy

Yihui QI, Jianting GUO and Chuanyong GUIDepartment of Superalloys, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China

摘 要：<正> The microstructure and creep behavior of a DS NiAI-Fe（Nb） multiphase intermetallic alloy have been investigated. This alloyexhibits dendritic structure, in which dendritic arm is β-（Ni,Fe）（Fe,Al） phase surrounded by interdendritic region of γ’/γ phase.The results of the creep test indicated that all of the creep curves have similar characteristic, which is a short primary creepstage and a dominant steady state creep stage, and the creep strain ranges from 18% to 52%. The apparent stress exponentand the apparent activation energy were analyzed and discussed. The mechanism of the creep deformation was also analyzedby the observation of TEM.

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