High-temperature oxidation behavior of (Hf0.2Zr0.2Ta0.2Nb0.2Ti 0.2)C high-entropy ceramics in air

作者：Ye, Beilin; Wen, Tongqi; Chu, Yanhui^*

来源：Journal of the American Ceramic Society, 2020, 103(1): 500-507.

DOI：10.1111/jace.16725

• high-entropy ceramics
• metal carbides
• oxidation behavior

High-entropy metal carbides have recently been arousing considerable interest. Nevertheless, their high-temperature oxidation behavior is rarely studied. Herein the high-temperature oxidation behavior of (Hf0.2Zr0.2Ta0.2Nb0.2Ti0.2)C high-entropy metal carbide (HEC-1) was investigated at 1573-1773 K in air for 120 minutes. The results showed that HEC-1 had good oxidation resistance and its oxidation obeyed a parabolic law at 1573-1673 K, while HEC-1 was completely oxidized after isothermal oxidation at 1773 K for 60 minutes and thereby its oxidation followed a parabolic-linear law at 1773 K. An interesting triple-layered structure was observed within the formed oxide layer at 1673 K, which was attributed to the inward diffusion of O-2 and the outward diffusion of Ti element and CO or CO2 gaseous products.