Effect of Y additions on the oxidation behavior of vacuum arc melted refractory high-entropy alloy AlMo0.5NbTa0.5TiZr at elevated temperatures. (July 2022)

• Record Type: Journal Article
• Authors: Lu, Shuaidan; Li, Xiaoxiao; Liang, Xiaoyu; He, Jiahua; Shao, Wenting; Li, Kuanhe; Chen, Jian
• Is Part Of: Vacuum. Volume 201(2022)
• Publication Date: 2022-07
• Subjects: Refractory high entropy alloys -- Oxidation -- Y addition -- Volatile oxidation -- Power-law; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2022.111069
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: The effects of yttrium (Y) addition on the oxidation resistance of AlMo0.5 NbTa0.5 TiZr refractory high entropy alloys (RHEAs) were investigated. The oxidation consists of the formation of passivating and complex oxide layer and the volatile oxidation of Mo, resulting in a power-law dependence of weight gain throughout the early stage of oxidation. Y addition induced the formation of continuous AlNbO4 -based oxidation scales and reduced the volatile oxidation of Mo. The pegs-oxidized Y formed in the interfaces between oxide and substrate improved the adherence of the oxide scale. The high content of Y was disadvantageous to resisting oxidation at high temperature. Highlights: 0.6 at.% Y addition makes the AlMo0.5 NbTa0.5 TiZr RHEA possess a better oxidation resistance at 800–1000 °C. Y addition induces the formation of continuous AlNbO4 -based complex oxidation scales over the dendritic regions. The pegs-oxidized Y formed in the interfaces of oxide and metal could improve the adherence of the oxide scale.