Synthesis of high-entropy ceramics (Y0.2Yb0.2Lu0.2Eu0.2Er0.2)3Al5O12 by electron beam heating

Abstract

High-entropy ceramic materials are promising for creating functional ceramics for various purposes. The unique properties of such materials make it possible to create new thermal barrier coatings based on them. Reducing costs, time and simplifying the technology of synthesis of high-entropy ceramics is the subject of numerous studies. In this work, the synthesis of high-entropy ceramics (Y0,2Yb0,2Lu0,2Eu0,2Er0,2)3Al5O12 in a powerful beam of fast electrons was carried out for the first time. A powder mixture of initial oxides, placed in the volume of a massive copper cell, was exposed in air to a short-term exposure to a beam of powerful fast electrons with an energy of 2 MeV and a beam current of 12 mA. The speed of movement of the cuvette with the powder mixture under the beam was 1 cm/s. The total irradiation time was 10 s. During the irradiation process, at least 96 % of the mass of the powder mixture melted, resulting in the formation of highly porous ceramic formations in the form of droplets. X-ray phase analysis showed that the melt droplets are high-entropy ceramics (Y0,2Yb0,2Lu0,2Eu0,2Er0,2)3Al5O12. The powder product remaining in the cuvette and not participating in the formation of droplets contains phases of the original oxides and intermediate phases of synthesized high-entropy ceramics. Electron microscopy with EDS showed a uniform distribution of elements on the surface and in the volume of the formed ceramic droplets.