An Atom Probe Tomography study of site preference and partitioning in a nickel-based superalloy

By P. Bagot, O. B. W. Silk, J. Douglas, S. Pedrazzini, D. Crudden, Tomas L Martin, M. Hardy, Michael Moody, R. Reed. 2017

142 citations recorded by the source corpus.

Abstract Atom Probe Tomography (APT) has been utilised for an in-depth examination of the commercial polycrystalline Ni-based superalloy RR1000, assessing compositions of the primary, secondary and tertiary γ′ phases. Clear differences in the phase chemistries are noted, particularly for the tertiary γ′ to which much of the alloy strength is attributed. Trace amounts of Hf are found to segregate strongly to the primary and secondary γ′ phases, but also exhibit an extended diffusion profile across the γ-γ′ interface up to 80 nm wide. Ti, Al and Mo demonstrate similar, yet not as pronounced diffusion profiles, indicating assumed phase chemistries may not be representative of those regions adjacent to the γ-γ′ interface. Within γ′, unique element site-occupancy preferences for this alloy were identified. Finally, the grain boundary chemistry across a γ-γ interface and that of an intragranular boride were analysed, identifying the latter as a mixed M 5 B 3 boride rich in Mo and Cr. These demonstrate further the depth of information on Ni-alloys accessible by APT, while the overall implications of results in comparison with other in-service/model alloys are also discussed.

Subfields: Biomedical Engineering, Mechanical Engineering, Metals and Alloys

View Paper: https://www.semanticscholar.org/paper/033de234235712f40c7af825c5497bc9019056a0

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In Biomedical Engineering

1. Baptiste Gault
2. G. Martin
3. Dierk Raabe
4. E. Chauvet
5. C. Tassin
6. J. Blandin
7. P. Kontis
8. R. Dendievel

In Mechanical Engineering

1. Baptiste Gault
2. E. Jägle
3. Junyang He
4. Dierk Raabe
5. G. Martin
6. R. Dendievel
7. Franz Roters
8. O. A. Zambrano

In Metals and Alloys

1. Dierk Raabe
2. Baptiste Gault
3. C. Tasan

Citations in the corpus

• Hot cracking mechanism affecting a non-weldable Ni-based superalloy produced by selective electron Beam Melting (2018, background): “EDX and APT results as well as literature data [8,29,42,43] show the presence of borides along the grain boundaries.”
• Atomic-scale grain boundary engineering to overcome hot-cracking in additively-manufactured superalloys (2019, result): “The segregation behavior observed here is in agreement with previous reports [26,32,33].”