Elemental effects on the oxidation of refractory compositionally complex alloys. (November 2022)

• Record Type: Journal Article
• Authors: Lo, Kai-Chi; Murakami, Hideyuki; Glatzel, Uwe; Yeh, Jien-Wei; Gorsse, Stéphane; Yeh, An-Chou
• Is Part Of: International journal of refractory metals & hard materials. Volume 108(2022)
• Publication Date: 2022-11
• Subjects: Refractory alloys -- Compositionally complex alloys -- Oxidation; Heat resistant alloys -- Periodicals; Refractory materials -- Periodicals; Metallography -- Periodicals; Alliages réfractaires -- Périodiques; Matériaux réfractaires -- Périodiques; Métallographie -- Périodiques; Heat resistant alloys; Metallography; Refractory materials; Periodicals; Electronic journals; 669.73
• DOI: 10.1016/j.ijrmhm.2022.105918
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: 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 Nb2 Zr6 O17, Ta2 Zr6 O17, ZrTiO4, and VTa9 O25, resulting in severe internal oxidation. Mo appeared to be effective in suppressing internal oxidation, but it could form non-protective MoTiTa8 O25 . 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. Graphical abstract: Unlabelled Image Highlights: The oxidation of refractory compositionally complex alloys is systematically studied at 1000 °C. Multiple refractory complex oxides are observed and analysed. The effects of the selected elements on the oxidation behaviours are discussed. Complex oxide formation is explained with thermodynamic simulation.