Oxidation Behavior of the AlMo0.5NbTa0.5TiZr Chemically Complex Alloy
- The chemically complex alloys that contain mostly refractory elements (rCCAs), may be highly resistant to heat and load, which makes them attractive candidates for use at extremely high temperatures associated with technological applications such as aeroengine turbines. However, the oxidation behavior remains an emerging field within the CCA community. The fully heat treated AlMo0.5NbTa0.5TiZr rCCA contains a dual-phase microstructure that resembles the γ/ γ’ pattern of the well-known Ni-base superalloys, however with a continuous Al-Zr-Ti-rich B2 ordered matrix embedding Mo-Nb-Ta-rach bcc precipitates. The question thus arises what is the oxidation behavior of this rCCA alloy? In this study, this question is addressed via in situ and ex situ X-ray diffraction (XRD) in dry and humid air in the 800–1000 °C regime. Electron microscopic investigations complement the findings.
In situ synchrotron experiments were carried out at the KMC2 beamline of the Helmholtz Zentrum Berlin (HZB),The chemically complex alloys that contain mostly refractory elements (rCCAs), may be highly resistant to heat and load, which makes them attractive candidates for use at extremely high temperatures associated with technological applications such as aeroengine turbines. However, the oxidation behavior remains an emerging field within the CCA community. The fully heat treated AlMo0.5NbTa0.5TiZr rCCA contains a dual-phase microstructure that resembles the γ/ γ’ pattern of the well-known Ni-base superalloys, however with a continuous Al-Zr-Ti-rich B2 ordered matrix embedding Mo-Nb-Ta-rach bcc precipitates. The question thus arises what is the oxidation behavior of this rCCA alloy? In this study, this question is addressed via in situ and ex situ X-ray diffraction (XRD) in dry and humid air in the 800–1000 °C regime. Electron microscopic investigations complement the findings.
In situ synchrotron experiments were carried out at the KMC2 beamline of the Helmholtz Zentrum Berlin (HZB), with a wavelength of 1.5418 Å at 800 and 950 °C under dry and humid (≈ 40% rH, laboratory air) air for 12 h. Scanning and transmission electron microscopy was performed before and after exposure to spatially resolve the scale development ex situ. In general, 12 h exposure led to an oxide scale which internal oxidation reaches several tens of microns, and which is dominated by Zr-, Ti- and Mo-containing oxides although aluminum oxide was also always present. Main differences are observed between temperatures, while the humidity played a lesser role.…


| Autor*innen: | Patricia Suárez OcañoORCiD, Leonardo Agudo JácomeORCiD |
|---|---|
| Koautor*innen: | Anna Maria ManzoniORCiD, Juho Lehmusto |
| Dokumenttyp: | Vortrag |
| Veröffentlichungsform: | Präsentation |
| Sprache: | Englisch |
| Jahr der Erstveröffentlichung: | 2023 |
| Organisationseinheit der BAM: | 5 Werkstofftechnik |
| 5 Werkstofftechnik / 5.1 Mikrostruktur Design und Degradation | |
| DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten |
| Freie Schlagwörter: | Electron microscopy; High entropy superalloy; High temperature oxidation; In situ synchrotron diffraction |
| Themenfelder/Aktivitätsfelder der BAM: | Material |
| Material / Degradationsmechanismen | |
| Veranstaltung: | International Conference on High Entropy Materials (ICHEM) 2023 |
| Veranstaltungsort: | Knoxville, TN, USA |
| Beginndatum der Veranstaltung: | 18.06.2023 |
| Enddatum der Veranstaltung: | 22.06.2023 |
| Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
| Datum der Freischaltung: | 06.08.2025 |
| Referierte Publikation: | Nein |
| Eingeladener Vortrag (wissenschaftliche Konferenzen): | Nein |

