FEATURES OF THE STRUCTURE AND HEAT RESISTANCE OF HIGH-EN- TROPY ALLOYS OF THE FeCrCuNiAl AND FeCrCuNiMn SYSTEMS

Procesi littâ, 2024, Vol 3 (157), 46-52

Abstract

High entropy alloys (HEAs) are an unique class of metallic materials that nominally contain five or more elements in nearly equiatomic proportions. Alloys with high entropy are of great interest primarily because the high configurational entropy in such alloys blocks the formation of intermetallic and chemical compounds. As a result, a single-phase structure of a solid solution, or a combination of solid solutions is formed. The crystal lattice of high-entropy alloys with an one- or two-phase solid solutions structure undergoes significant deformation and can create new, previously unattainable, combinations of properties. Their research is currently at the stage of initial accumulation of information, but according to the already available data, the prospects for their use as heat-resistant materials are very promising. The paper contains information on the phase composition and structure of the HEA of FeNiCrCuAl and FeNiCrCuMn systems. It is shown that they have a microstructure with dendritic morphology, and consist of solid solutions with bcc and fcc crystal lattices. The influence of the chemical composition, such as aluminum and chromium, on the surface oxidation of HEA at temperatures of 900 °C and 1000 °C in the artificial air atmosphere was investigated by the gravimetric analysis method. It was established that alloying with aluminum and chromium, in general, had a positive effect on the heat resistance of the alloys, and the chromium content of 18 wt. % provided them long-term resistance to oxidation at a temperature of 1000 °C.