Elemental effects on the oxidation of refractory compositionally complex alloys

Kai-Chi Lo (1, 2) , Hideyuki Murakami (3, 4) , Uwe Glatzel (5) , Jien-Wei Yeh (1, 2) , Stéphane Gorsse (6) , An-Chou Yeh (1, 2)

1 Department of Materials Science and Engineering
2 High Entropy Materials Center
3 Research Center for Structural Materials
4 Department of Nanoscience and Nanoengineering
5 University of Bayreuth
6 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

The oxidation of refractory compositionally complex alloys (RCCAs) is one of the most critical subjects for their high temperature applications. In this work, several RCCAs were systematically designed and isothermally oxidised at 1000 °C for up to 24 h; the elemental effects of Al, Cr, Mo, Nb Ta, Ti, V, and Zr on the oxidation of the RCCAs were studied. It was found that Al, Cr, Ti could enhance the oxidation resistance of the RCCAs by promoting the formation of rutile-type AlTaO4, CrTaO4, and their related oxides, while Zr and V formed non-protective oxides such as Nb2Zr6O17, Ta2Zr6O17, ZrTiO4, and VTa9O25, resulting in severe internal oxidation. Mo appeared to be effective in suppressing internal oxidation, but it could form non-protective MoTiTa8O25. Ta was slightly more beneficial than Nb for reducing the oxidation mass gain. This study provides insights on the elemental effects on the oxidation and guidelines for improving the oxidation resistance of RCCAs.

Mots clés: Refractory alloys; Compositionally complex alloys; Oxidation

Domaines: Matériaux

Kai-Chi Lo, Hideyuki Murakami, Uwe Glatzel, Jien-Wei Yeh, Stéphane Gorsse, et al.. Elemental effects on the oxidation of refractory compositionally complex alloys. International Journal of Refractory Metals and Hard Materials, 2022, 108, pp.105918. ⟨10.1016/j.ijrmhm.2022.105918⟩. ⟨hal-03719376⟩