Oxidation behaviour of Ti-V-Cr-Nb-Ta and Al-Ti-V-Cr-Ta refractory high entropy alloys: Effects of Nb and Al substitutions

Kieran Rivers; Bradley Young; Yuanbo T. Tang; Bo-Shiuan Li; Angus J. Wilkinson; David E.J. Armstrong; Junliang Liu

Materials & Design (Oct 2024)

Oxidation behaviour of Ti-V-Cr-Nb-Ta and Al-Ti-V-Cr-Ta refractory high entropy alloys: Effects of Nb and Al substitutions

Kieran Rivers,
Bradley Young,
Yuanbo T. Tang,
Bo-Shiuan Li,
Angus J. Wilkinson,
David E.J. Armstrong,
Junliang Liu

Affiliations

Kieran Rivers: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
Bradley Young: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
Yuanbo T. Tang: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK; School of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT, UK
Bo-Shiuan Li: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK; Department of Mechanical and Electromechanical Engineering, National Sun-Yat Sen University, No. 70 Lien-hai Rd., Kaohsiung, Taiwan
Angus J. Wilkinson: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
David E.J. Armstrong: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
Junliang Liu: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK; Department of Nuclear Engineering and Engineering Physics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, WI 53706, USA; Corresponding author.

Journal volume & issue: Vol. 246
p. 113370

Abstract

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Refractory high entropy alloys (RHEAs) are candidate materials for nuclear and other high-temperature applications, due to their high-temperature strength, good irradiation resistance, and high melting temperatures. However, a significant issue with current RHEAs is that those exhibiting good mechanical properties tend to show poor oxidation resistance, and vice versa. In this paper, the oxidation kinetics of four RHEAs (20Ti-20V-20Cr-20Nb-20Ta, 25Ti-25V-5Cr-20Nb-25Ta, 20Al-20Ti-20V-20Cr-20Ta, and 14Al-24Ti-24V-14Cr-24Ta alloys) were investigated in an air atmosphere at 1000 °C. As-prepared and oxidised samples were characterised by a combination of state-of-the-art microscopy techniques. By replacing Nb with Al, the two Al-containing alloys were observed to form a less porous oxide microstructure, showing significant improvement in their oxidation resistance. As a result of oxygen/nitrogen ingress during oxidation and associated phase-segregation at high temperatures, the hardness of the underlying metal matrix of the RHEAs increased by approximately 5 GPa.

Published in Materials & Design

ISSN: 0264-1275 (Print); 1873-4197 (Online)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials
Website: https://www.journals.elsevier.com/materials-and-design

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