Atomic Structure and Chemical Composition of Planar Fault Structures in Co-Base Superalloys

Lenz M, Wu M, He J, Makineni SK, Gault B, Raabe D, Neumeier S, Spiecker E (2020)

Publication Type: Conference contribution

Publication year: 2020

Publisher: Springer Science and Business Media Deutschland GmbH

Pages Range: 920-928

Conference Proceedings Title: Minerals, Metals and Materials Series

Event location: Seven Springs, PA US

ISBN: 9783030518332

DOI: 10.1007/978-3-030-51834-9_90

Abstract

We report atomic structures and chemical compositions of defects associated to planar faults in a creep deformed Co-base superalloy and discuss their formation and contribution to plastic deformation. The multinary single crystalline Co-base superalloy was creep deformed under tension along [ 001 ] -direction at 850 °C and 400 MPa. The creep microstructure comprises a high density of planar defects. Solute segregation to superlattice intrinsic stacking faults (SISF) is characterized via EDXS analysis of a statistically relevant number of faults and compared at different creep stages. The amount of solute segregation shows negligible difference at different creep stages indicating that segregation directly occurs during planar fault formation and does not significantly evolve afterward. Based on the observation and analysis of Frank partial dislocations with a/3⟨111⟩ Burgers vectors terminating SISF, we discuss a new route to SISF formation via dislocation climb. Additionally, two more complex fault structures are analyzed, and potential formation mechanisms are discussed. The first of these structures is a terminating end of an SISF where an a/3⟨112⟩ partial dislocation splits up into two closely spaced a/6⟨112⟩ partials separated by an SESF. The second structure consists of two parallel SISFs connected by an anti-phase boundary (APB). All deformation mechanisms described in this study show an involvement of solute segregation directly affecting formation and propagation of creep defects by changing planar fault energies and chemical environments of dislocations. Solute segregation is therefore expected to be a key to future alloy design by enabling control of creep deformation mechanisms in specific temperature and stress regimes.

Authors with CRIS profile

Malte Lenz Lehrstuhl für Werkstoffwissenschaften (Mikro- und Nanostrukturforschung) Mingjian Wu Lehrstuhl für Werkstoffwissenschaften (Mikro- und Nanostrukturforschung) Steffen Neumeier Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Erdmann Spiecker Lehrstuhl für Werkstoffwissenschaften (Mikro- und Nanostrukturforschung)

Additional Organisation(s)

Interdisziplinäres Zentrum, Center for Nanoanalysis and Electron Microscopy (CENEM) Lehrstuhl für Werkstoffwissenschaften (Mikro- und Nanostrukturforschung) Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)

Related research project(s)

B03 (FP3): Einkristalline Co-Basis Superlegierungen (SFB/TRR 103) SFB/TRR 103 Jan. 1, 2020 - Dec. 31, 2023 High resolution transmission electron microscopy investigation of the atomic structure of defects and interfaces in single crystal superalloys (A07) (TRR 103) TRR 103: Vom Atom zur Turbinenschaufel - wissenschaftliche Grundlagen für eine neue Generation einkristalliner Superlegierungen Jan. 1, 2012 - Jan. 1, 2015

Involved external institutions

Max-Planck-Institut für Eisenforschung GmbH (MPIE) / Max Planck Institute for Iron Research DE Germany (DE)

How to cite

APA:

Lenz, M., Wu, M., He, J., Makineni, S.K., Gault, B., Raabe, D.,... Spiecker, E. (2020). Atomic Structure and Chemical Composition of Planar Fault Structures in Co-Base Superalloys. In Sammy Tin, Mark Hardy, Justin Clews, Jonathan Cormier, Qiang Feng, John Marcin, Chris O'Brien, Akane Suzuki (Eds.), Minerals, Metals and Materials Series (pp. 920-928). Seven Springs, PA, US: Springer Science and Business Media Deutschland GmbH.

MLA:

Lenz, Malte, et al. "Atomic Structure and Chemical Composition of Planar Fault Structures in Co-Base Superalloys." Proceedings of the 14th International Symposium on Superalloys, Superalloys 2021, Seven Springs, PA Ed. Sammy Tin, Mark Hardy, Justin Clews, Jonathan Cormier, Qiang Feng, John Marcin, Chris O'Brien, Akane Suzuki, Springer Science and Business Media Deutschland GmbH, 2020. 920-928.

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