Synchrotron Sub-μ X-ray Tomography of Kirkendall Porosity in a Diffusion Couple of Nickel-Base Superalloy and Nickel after Annealing at 1250 °C
Journal article, 2021

Kirkendall porosity that forms during interdiffusion in a diffusion couple of nickel-base superalloy CMSX-10 with pure nickel is investigated. The diffusion experiments are conducted at a temperature of 1250 °C, where the strengthening γ′-phase is partially dissolved. The porosity is studied by X-ray sub-μ tomography with a spatial resolution of about 0.353 μm3 at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. It is found that depending on the distance from the interface the Kirkendall pores take different shapes: octahedral, rounded pyramidal, drop shaped, dendritic, pear shaped, and joint shapes. Such a variety of pore morphologies indicates a complex multistage process of porosity nucleation and growth under vacancy supersaturation of different degrees. The experimental findings are interpreted on the basis of the results of diffusion modeling. It is shown that the kinetics of porosity growth is essentially influenced by the dissolution of the γ′-phase.

porous materials

three-dimensional tomographies

synchrotron radiations

diffusions

nickel alloys

Author

Alexander Epishin

Technische Universität Berlin

Bettina Camin

Technische Universität Berlin

Lennart Hansen

Technische Universität Berlin

Anton Chyrkin

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry

Gert Nolze

Federal Institute for Materials Research and Testing

Advanced Engineering Materials

1438-1656 (ISSN) 1527-2648 (eISSN)

Vol. In Press

Subject Categories

Physical Chemistry

Other Physics Topics

Metallurgy and Metallic Materials

DOI

10.1002/adem.202001220

More information

Latest update

2/3/2021 1