Property tuning and additive manufacturing of refractory high-entropy alloys

The refractory high-entropy alloys (RHEAs) usually form a multi-principal elements alloy with equal atomic ratio or near equal atomic ratio via adding a variety of high melting point elements, showing simple phase composition and excellent high temperature properties, and processing a broad application prospect in the field of superalloy. Based on the performance characteristics and preparation process of RHEAs, and from the perspective of the current situation and challenges in fabrication and forming, the property tuning methods and its research progress of RHEAs were summarized, as well as the achieved breakthrough and the facing dilemma of the additive manufactured RHEAs. A prospection on the composition design and optimization, material preparation and processing, and additive manufactured forming of RHEAs was also proposed. The following suggestions are put forward for the key research trend of RHEAs in the future: tuning phase composition and phases interface to overcome the strength-ductility trade-off of RHEAs, designing alloys by combining the mature traditional strengthening and toughening theory with the properties of RHEAs, modifying the formability and properties of RHEAs by drawing support from the processing characteristics of additive manufacturing technology, and investigating the servicing performance and failure mechanism in high temperature or multi-field coupling condition of RHEAs.