A review of the synthesis, processing parameters, characterization and mechanical behavior of refractory high-entropy alloys

Refractory high-entropy alloys, or RHEAs, have attracted the interest of scientists, academics, and engineers in the last ten years due to their functional characteristics and superior mechanical. Researchers favor RHEAs due to their significant application potential in high-temperature, corrosive, and irradiated environments, including aerospace, maritime, and nuclear equipment. In this review paper, the preparation technologies of RHEAs are summarized for bulk and coating, and the advantages and drawbacks of each approach are evaluated. The characteristics of RHEAs, including their wear resistance, mechanical characteristics, corrosion resistance, and oxidation resistance are examined. This document outlines the existing scientific issues related to RHEAs, providing information for their future research and application, especially as plasma-facing materials in reactors of nuclear fusion. This study emphasizes the significance of the interaction among elements composition, milling duration, and sintering conditions in optimizing the microstructure and properties of RHEAs for advanced applications. Generally, the mechanical properties act as important indicators of performance for resultant RHEAs, influenced by factors such as alloying elements, crystal structure, processing techniques, and their parameters. Literature indicates that the incorporation of refractory elements like Ti, Zr, Hf, Cr, and Re, along with a minor inclusion of non-refractory metal elements such as Al, Si, Co, or Ni, can enhance mechanical behavior, particularly in terms of compression properties, bulk hardness, and wear resistance.