Insights into the exploration of refractory high-entropy alloys: from the design to the deformation mechanisms of these complex materials

Among all the possible new materials solutions for advanced applications, huge research effort has been dedicated to the study of high-entropy alloys (HEAs), and more generally of complex concentrated alloys (CCA’s). The exploration of refractory-based HEA/CCA compositions has been initiated in 2010 under the impetus of the Air Force Research Laboratory (USA) and inspired by the desire to develop new structural alloys stressed under extreme conditions (T>1200°C). Ten years after, the field has considerably expanded and some new interesting results have been proposed recently. Thus, the presentation will first provide an overview of the main features of these complex alloys based on processing methods, composition and microstructures. In the second part, mechanical properties, strengthening and deformation mechanisms and will be discussed in light of the very recent results published in literature. Finally, future directions of research and development will be discussed.