Up-and-coming high-temperature materials, refractory high entropy alloys, are suffering from lower oxidation resistance, restricting their applications in the aerospace field. In this study, two novel treatments of Al-deposited and remelted were developed to refine the microstructure and enhance the oxidation resistance of refractory high entropy alloy using electron beam freeform fabrication (EBF³). Finer and short-range ordering structures were observed in the remelted sample, whereas the Al-deposited sample showcased the formation of silicide and intermetallic phases. High-temperature cyclic and isothermal oxidation tests at 1000 °C were carried out. The total weight gain after 60 h of cyclic oxidation decreased by 17.49 % and 30.46 % for the remelted and deposited samples, respectively, compared to the as-cast state. Oxidation kinetics reveal an evident lower mass gain and oxidation rate in the treated samples. A multilayer oxide consisting of TiO₂+Al₂O₃+SiO₂+AlNbO₄ was studied for its excellent oxidation resistance. The oxidation behavior of rutile, corundum and other oxides was analyzed using first principles calculations and chemical defect analysis. Overall, this research, which introduces novel treatments, offers promising insights for enhancing the inherent oxidation resistance of refractory high entropy alloys.

新兴的高温材料——难熔高熵合金，其抗氧化性能较低，限制了其在航空航天领域的应用。在这项研究中，开发了两种新型的沉积铝和重熔处理方法，以使用电子束自由成形（EBF ³ ）细化耐火高熵合金的微观结构并增强其抗氧化性。在重熔样品中观察到更精细和短程的有序结构，而沉积铝的样品则显示出硅化物和金属间相的形成。进行了1000℃的高温循环和等温氧化试验。与铸态相比，重熔样品和沉积样品在 60 小时循环氧化后的总重量增加分别减少了 17.49% 和 30.46%。氧化动力学显示经处理的样品的质量增益和氧化速率明显较低。研究了由TiO ₂ +Al ₂ O ₃ +SiO ₂ +AlNbO ₄组成的多层氧化物其优异的抗氧化性。使用第一原理计算和化学缺陷分析来分析金红石、刚玉和其他氧化物的氧化行为。总的来说，这项研究引入了新颖的处理方法，为增强难熔高熵合金的固有抗氧化性提供了有希望的见解。