Effect of Al content on the oxidation behavior of refractory high-entropy alloy AlMo0.5NbTa0.5TiZr at elevated temperatures. (June 2022)

• Record Type: Journal Article
• Authors: Lu, Shuaidan; Li, Xiaoxiao; Liang, Xiaoyu; Shao, Wenting; Yang, Wei; Chen, Jian
• Is Part Of: International journal of refractory metals & hard materials. Volume 105(2022)
• Publication Date: 2022-06
• Subjects: Refractory high entropy alloys -- Oxidation -- Al content -- Volatile oxidation -- Oxidation behavior; 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.2022.105812
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: The effects of Al content on the oxidation resistance of AlMo0.5 NbTa0.5 TiZr refractory high entropy alloys (RHEAs) were investigated. The oxidation obeys a power-law passivating oxidation at the early stage, followed by a transformation to linear oxidation. Increasing Al content reduces the mass change of forming the full coverage of passivating scale and prolongs the passivation duration of alloys. Higher Al content benefits the formation of AlNbO4 and AlTaO4 instead of Nb2 O5 and Ta2 O5, which has a positive effect on oxidation resistance of alloys. The fracture of scales generally occurs at the mass gain of 15 mg∙cm −2 roughly and leads to the transformation to linear oxidation. Highlights: The oxidation of Alx Mo0.5 NbTa0.5 TiZr obeys a power-law oxidation, followed by a transformation to linear oxidation. Increasing Al content reduces the mass change of forming passivating scale and prolongs the passivation duration of alloys Higher Al content benefits the formation of AlNbO4 and AlTaO4 and improves the oxidation resistance of alloys.