Composition design and preparation process of refractory high-entropy alloys: A review

Abstract

Refractory high-entropy alloys (RHEAs) with excellent comprehensive mechanical properties at high temperature are a new research focus in the field of materials. In this paper, the compositional design theory and the simulation research based on first-principles of density functional theory (DFT) for RHEAs were introduced. The research status of compositional optimization, doping non-metallic elements and functional phases, and phase structure regulation for RHEAs were summarized. In addition, the process characteristics of smelting, powder metallurgy, magnetron sputtering and laser cladding were reviewed, and the feasibility and difficulties of preparing RHEAs by extreme high-speed laser cladding (EHLC) were analyzed. Finally, the following suggestions were put forward for the development direction of RHEAs: improving the theory and simulation study of RHEAs composition design, investigating the strengthening effect of doping non-metallic elements and functional phases in RHEAs, paying attention to the synergistic effect between different phase structures, optimizing the process of preparing RHEAs by laser cladding to realize direct forming of parts, and expanding the application of EHLC in preparation of RHEAs coatings.