Příprava a vlastnosti slitin s vysokou entropií

Abstract

This thesis deals with high-entropy alloys. In the theoretical part, the knowledge about the basic characteristics of these alloys, the conditions of their formation, their classification and chemical composition, preparation methods and their properties are summarized. The experimental part is focused on the possibility of preparation of CrCoFeCuNi alloy by the induction melting with centrifugal casting, which was subsequently heat treated at 900 °C for 24 hours to achieve a single-phase structure. The as-cast and heat treated alloy were subjected to the structural and chemical analysis using scanning electron microscopy and energy dispersion analysis. It was found that the structure in the as-cast alloy contains except matrix solid solution another two phases – Cr-rich phase and Cu-rich phase. According to the available binary and ternary diagrams, they are also solid solutions. During the heat treatment, there was no “dissolution” of these secondary phases and structural characteristics were not very different from the as-cast state.