Influence of refractory and platinum group metals on the microstructure and thermo-physical properties of Co-Al-W-based superalloys

Köbrich M, Förner A, Volz N, Zenk C, Fries SG, Göken M, Neumeier S (2023)

Publication Type: Journal article

Publication year: 2023

Journal

Book Volume: 947

Article Number: 169542

DOI: 10.1016/j.jallcom.2023.169542

Abstract

The influence of various alloying elements on Co-Al-W based superalloys has been investigated in detail since the discovery of the Co3(Al,W) phase. However, a full picture on the role of the refractory and platinum group elements is still lacking. Accordingly, this work covers the microstructural changes and phase stability in Co9Al9W-X superalloys with 2 at% Zr, Ru, Rh, Pd, Hf, Re, Ir, and Pt. The experimental findings are compared with thermodynamic calculations. Generally, alloying with refractory and platinum group elements preserves γ/γ′ microstructures, but causes the formation of additional intermetallic phases. Electron backscatter diffraction and energy dispersive X-ray spectroscopy reveal that Ru, Ir, and Pt cause discontinuous formation of β (B2) and χ (D019) phases whereas in the Re-containing alloy β and µ (D85) precipitates are present along the grain boundaries. Also unidentified Hf- and Zr-rich phases form in the alloys containing these elements. Additionally, differential scanning calorimetry measurements and scanning electron microscopy analysis indicate an increasing γ′ solvus temperature as well as γ′ volume fraction for most of the refractory and platinum group elements. This can be explained by their γ′/γ partitioning behavior, which has been examined by atom probe tomography.

Authors with CRIS profile

Additional Organisation(s)

Involved external institutions

Ruhr-Universität Bochum (RUB) Germany (DE)

How to cite

APA:

Köbrich, M., Förner, A., Volz, N., Zenk, C., Fries, S.G., Göken, M., & Neumeier, S. (2023). Influence of refractory and platinum group metals on the microstructure and thermo-physical properties of Co-Al-W-based superalloys. Journal of Alloys and Compounds, 947. https://doi.org/10.1016/j.jallcom.2023.169542

MLA:

Köbrich, Manuel, et al. "Influence of refractory and platinum group metals on the microstructure and thermo-physical properties of Co-Al-W-based superalloys." Journal of Alloys and Compounds 947 (2023).

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