Current development of body-centered cubic high-entropy alloys for nuclear applications

High-entropy alloys greatly expand the alloy design range and offer new possibilities for improving material performance. Based on the worldwide research efforts in the last decade, the excellent mechanical properties and promising radiation and corrosion resistance of this group of materials have been demonstrated. High-entropy alloys with body-centered cubic (BCC) structures, especially refractory high-entropy alloys, are considered as promising materials for high-temperature applications in advanced nuclear reactors. However, the extreme reactor conditions including high temperature, high radiation damage, high stress, and complex corrosive environment require a comprehensive evaluation of the material properties for their actual service in nuclear reactors. This review summarizes the current progress on BCC high-entropy alloys from the aspects of neutron economy and activation, mechanical properties, high-temperature stability, radiation resistance, as well as corrosion resistance. Although the current development of BCC high-entropy alloys for nuclear applications is still at an early stage as the large design space of this group of alloys has not been fully explored, the current research findings provide a good basis for the understanding and prediction of material behaviors with different compositions and microstructures. Further in-depth understanding of the degradation mechanisms and characterization of material properties in response to conditions close to reactor environment are necessary. A critical down-selection of potential candidates is also crucial for further comprehensive evaluation and engineering validation.