Materials Today Advances ( IF 10 ) Pub Date : 2020-08-20 , DOI: 10.1016/j.mtadv.2020.100104 S. Sheikh , L. Gan , A. Ikeda , H. Murakami , S. Guo
Refractory high-entropy alloys (RHEAs) are widely studied because of their promising potential for ultrahigh-temperature applications. One key challenge towards the development of RHEAs as high-temperature structural materials is to concurrently achieve optimum oxidation resistance and mechanical properties. Here in this work, the effect of alloying on the oxidation behavior of ductile RHEAs was studied. Specifically, a ductile RHEA, Al0.5Cr0.25Nb0.5Ta0.5Ti1.5, was alloyed with Al and Zr aiming to improve its oxidation resistance. The two modified RHEAs, Al0.75Cr0.25Nb0.5Ta0.5Ti1.5 and Al0.5Cr0.25Nb0.5Ta0.5Ti1.5Zr0.01, indeed show enhanced oxidation resistance at 800 °C and 1,100 °C, compared with Al0.5Cr0.25Nb0.5Ta0.5Ti1.5. In addition, all three RHEAs studied here show an excellent oxidation resistance at 800 °C compared with other RHEAs, although there is still a large space to further improve their performance at 1,100 °C. Internal oxidation and even nitridation are still present after oxidation exposure, indicating further efforts are required to form protective oxide scales on the surface of ductile RHEAs. Nevertheless, the work is expected to shed some light on future directions of improving the oxidation of ductile RHEAs, via the alloying route.
中文翻译:
合金化对延性Al 0.5 Cr 0.25 Nb 0.5 Ta 0.5 Ti 1.5难熔高熵合金的氧化行为的影响
由于难熔高熵合金(RHEA)具有超高温应用前景,因此被广泛研究。RHEA作为高温结构材料的发展面临的一项主要挑战是同时实现最佳的抗氧化性和机械性能。在本文中,研究了合金化对延性RHEAs氧化行为的影响。具体地,将延性的RHEA,Al 0.5 Cr 0.25 Nb 0.5 Ta 0.5 Ti 1.5与Al和Zr合金化以提高其抗氧化性。两种改性的RHEA,Al 0.75 Cr 0.25 Nb 0.5 Ta 0.5 Ti 1.5和Al 0.5的Cr 0.25的Nb 0.5的Ta 0.5的Ti 1.5 Zr的0.01,在800℃和1100℃,用Al相比的确显示出增强的耐氧化性0.5的Cr 0.25的Nb 0.5的Ta 0.5钛1.5。此外,尽管在1100°C下仍有较大的空间可进一步改善其性能,但本文研究的所有三种RHEA在800°C时均表现出优异的抗氧化性。暴露于氧化后,内部氧化甚至氮化仍然存在,这表明需要进一步努力在延性RHEA表面上形成保护性氧化皮。然而,预计该工作将为通过合金化途径改善延性RHEAs氧化的未来方向提供一些启示。