Xe Ion Irradiation-Induced Microstructural Evolution and Hardening Effect of Nickel-Base Superalloy

The nickel-base superalloy Hastelloy N was irradiated using 1 MeV Xe20+ and 7 MeV Xe26+ ions with displacement damage ranging from 0.5 dPa to 10 dPa at room temperature (RT). The irradiated Ni-based superalloy was characterized with transmission electron microscopy (TEM), XRD, and nanoindenter to determine the changes in microstructural evolution and nanoindentation hardness. The TEM results showed that ion irradiation induced a large number of defects such as black spots and corrugated structures and the second phase was rapidly amorphized after being irradiated to a fluence of 0.5 dPa. The XRD results showed that the Hastelloy N alloy sample did not undergo lattice distortion after ion irradiation. An obvious irradiation hardening phenomenon was observed in this study, and the hardness increased with Xe ion fluence. The pinning effect in which the defects can become obstacles to the free movement of dislocation may be responsible for the irradiation-induced hardening.

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Microstructural Evolution during Tensile Creep of a Single-Crystal Nickel-Base Superalloy

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.353-358.511 ◽

2007 ◽

Vol 353-358 ◽

pp. 511-514

Author(s):

Ying Li ◽

Hui Chen Yu ◽

Xue Ren Wu ◽

Xiao Guang Yang ◽

Duo Qi Shi

Keyword(s):

Electron Microscope ◽

Single Crystal ◽

Microstructural Evolution ◽

Tensile Creep ◽

Creep Process ◽

Nickel Base Superalloy ◽

Creep Tests ◽

Transmission Electron ◽

Nickel Base ◽

Base Superalloy

Tensile creep tests were conducted at 980°C under a constant stress on a single crystal nickel base superalloy. Some tests were interrupted at different stages during the creep process. The strain-time curves indicated that this alloy exhibited conventional primary, steady-state and tertiary stages at this temperature. The transmission electron microscope (TEM) observations of foils taken from the gauge sections of specimens were made to interpret the microstructural evolution that occurred during the creep process. It was found that the γ′ particles were rafted in the direction perpendicular to the applied stress. The acceleration of the creep rate was related to the change of the dislocation density.

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Temperature Dependence of Yield Strength and Elongation of the Nickel-base Superalloy IN 738 LC and the Corresponding Microstructural Evolution

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-1995-860309 ◽

1995 ◽

Vol 86 (3) ◽

pp. 190-197

Author(s):

Dirk Bettge ◽

Werner Österle ◽

Josef Ziebs

Keyword(s):

Yield Strength ◽

Temperature Dependence ◽

Microstructural Evolution ◽

Nickel Base Superalloy ◽

Nickel Base ◽

Base Superalloy

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Microstructural evolution of a single crystal nickel-base superalloy during thermal exposure

Materials Letters ◽

10.1016/s0167-577x(03)00359-8 ◽

2003 ◽

Vol 57 (29) ◽

pp. 4540-4546 ◽

Cited By ~ 38

Author(s):

L.R. Liu ◽

T. Jin ◽

N.R. Zhao ◽

Z.H. Wang ◽

X.F. Sun ◽

...

Keyword(s):

Single Crystal ◽

Microstructural Evolution ◽

Thermal Exposure ◽

Nickel Base Superalloy ◽

Nickel Base ◽

Base Superalloy

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Morphology of Precipitates in Ni-Al-Cr Intermetallic Alloy

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.130.159 ◽

2007 ◽

Vol 130 ◽

pp. 159-162

Author(s):

Mirosław Pilawa ◽

Elżbieta Jezierska

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Intermetallic Alloy ◽

Nickel Base Superalloy ◽

Transmission Electron ◽

Characteristic Features ◽

Secondary Precipitates ◽

Nickel Base ◽

Base Superalloy

Transmission electron microscopy was used to study various morphologies of ordered precipitates in Ni3Al-Cr intermetallic alloy. It was found that γ’ precipitates in the interdendritic regions have the microstructure of a nickel base superalloy with its characteristic features. In addition to the primary γ’ precipitates some fine secondary precipitates were found.

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