Preternatural Hexagonal High-Entropy Alloys: A Review

Recently, various topics on high-entropy alloys have been reported and great amounts of excellent properties have been investigated, including high strength, great corrosion resistance, great thermal stability, good fatigue and fracture properties, etc. Among all these research activities, high-entropy alloys tend to form face-centered-cubic (FCC) or body-centered-cubic (BCC) solid solutions due to their high-entropy stabilization effect, while the hexagonal structures are rarely reported. Up to now, the reported hexagonal high-entropy alloys are mainly composed of rare-earth elements and transitional elements. Their phase transformation and magnetic properties have also aroused wide concern. This study summarizes the above results and provides the forecast to the future.