The temperature dependent lattice misfit of rhenium and ruthenium containing nickel-base superalloys – Experiment and modelling

Neumeier S, Pyczak F, Göken M (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Materials and Design Elsevier

Book Volume: 198

Article Number: 109362

DOI: 10.1016/j.matdes.2020.109362

Abstract

The lattice misfit between γ and γ' phase is a key parameter in Ni-base superalloys. Resulting internal coherency stresses govern the microstructure, its evolution and mechanical properties. Here, the influence of important alloying elements Re and Ru on the misfit up to 1100 °C is investigated. Due to their preferred partitioning to γ, the addition of both leads to a stronger increase of the lattice parameter of γ than of γ' and thus to a more negative misfit. The overall content of Re and Ru influences significantly the evolution of the misfit with temperature. Alloys with high contents show an atypical behavior, where the magnitude of the negative misfit gets smaller at high temperatures. Alloys with a medium content exhibit a rather constant misfit and alloys with a low content or without Re and Ru follow the typical trend of a more negative misfit with increasing temperature. The observed differences are ascribed to different thermal expansion coefficients and particularly to the changing chemical composition of γ due to the dissolution of γ' precipitates. An advanced model for determining the misfit based on thermodynamic calculations is presented. Different approaches for determining lattice parameters and calculating lattice misfits are evaluated in the supplementary.

Authors with CRIS profile

Steffen Neumeier Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Mathias Göken Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)

Additional Organisation(s)

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

Involved external institutions

Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung GmbH (HZG) DE Germany (DE)

How to cite

APA:

Neumeier, S., Pyczak, F., & Göken, M. (2021). The temperature dependent lattice misfit of rhenium and ruthenium containing nickel-base superalloys – Experiment and modelling. Materials and Design, 198. https://doi.org/10.1016/j.matdes.2020.109362

MLA:

Neumeier, Steffen, F. Pyczak, and Mathias Göken. "The temperature dependent lattice misfit of rhenium and ruthenium containing nickel-base superalloys – Experiment and modelling." Materials and Design 198 (2021).

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