Influence of the oxidation on the optical properties of Mo-Si-Ti, Ta-Mo-Cr-Al and Ta-Mo-Cr-Ti-Al alloys

Three refractory element-based alloys were oxidized for 6 h at 1100 degrees C in air inside a muffle furnace and the way the oxidation, especially through the evolution of the surface composition and roughness, affects the optical properties of these materials is discussed here. The ternary Mo-20.0Si-52.8Ti (at%) serves as an example of Mobased alloys, while the equimolar Ta-Mo-Cr-Al (TMCA) and Ta-Mo-Cr-Ti-Al (TMCTA) are typical of the class of oxidation-resistant refractory compositionally complex alloys. The normal spectral emissivity of these three samples was increased due to the oxidation process. Oxidized TMCA and TMCTA exhibit a solar absorptivity higher than that of state-of-the-art Ni-based alloys used for solar receivers in concentrated solar power plants. Thus, the two refractory compositionally complex alloys are considered promising candidates for solar thermal energy conversion application.

Automated summary

This study discusses how the oxidation of refractory element-based alloys affects their optical properties, specifically through changes in surface composition and roughness. The results show that the oxidation process significantly increases the spectral emissivity of the samples. The oxidized TMCA and TMCTA alloys exhibit a higher solar absorptivity compared to state-of-the-art Ni-based alloys used in solar power plants, making them promising candidates for solar thermal energy conversion applications.