1. Creep behaviors of multiphase Ni3Al-based intermetallic alloy after 1000 °C-1000 h long-term aging at intermediate temperatures.
- Author
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Wu, Jing, Li, Chong, Wu, Yuting, Huang, Yuan, Xia, Xingchuan, and Liu, Yongchang
- Subjects
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ALLOYS , *DETERIORATION of materials , *CREEP (Materials) , *NICKEL-aluminum alloys , *HEAT resistant alloys - Abstract
The microstructure evolutions during 1000 °C-1000 h long-term aging and relevant 800 ~ 840 °C/220 ~ 300 MPa creep behaviors of a novelly designed multiphase Ni 3 Al-based intermetallic alloy were investigated. Results showed this alloy presented excellent intermediate temperature creep properties even after 1000 °C-1000 h long-term aging. A kind of bimodal R-type γ′ rafting structures were observed in the 800 °C/220 MPa creep process of the long-term aged alloy, and the creep resistance levels of three kinds of γ′ rafting structures were evaluated to be in the order of bimodal R-type γ′ rafting structures > R-type γ′ rafting structure > N-type γ′ rafting structure. The 1000 °C-1000 h long-term aging can promote the inhomogeneous precipitation of Cr 4.6 MoNi 2.1 phase at the edge γ′+γ dendrite area, which can play the role of pinning dislocations and inhibiting the further rafting and coarsening of the R-type γ′ rafts during creep. Differed from Ni-based alloys and other Ni 3 Al-based alloys, this long-term aged alloy exhibited abnormal four-stage creep characteristics, which consisted of atypical short steady-state creep stage with step fluctuant feature and atypical long accelerated creep stage with creep rate increasing at a constant rate. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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