Mechanical behavior of high-entropy alloys

Research in the field of high-entropy alloys has been surging since the 2010s. As widely acknowledged, research interests in this field are largely sparked by the enormous possibilities in compositions, microstructures, and properties. In the first decade of extensive investigations, while many avenues of research in this vibrant field are being continuously opened, a considerable portion of endeavors is directed toward two very fundamentally important aspects. One is the exploration of the huge compositional space and microstructures with the aid of thermodynamics and kinetics, while the other is the characterization and comprehension of their mechanical behavior from fundamental and practical perspectives. Each of these two aspects contains numerous, scattered, sometimes confusing or conflicting data and findings in the literature. Thanks to several excellent comprehensive reviews [1?3], the accomplishments and challenges in the first aspect are neatly presented to researchers in the field. Nonetheless, the second aspect, i.e., the mechanical behavior of high-entropy alloys, is still largely afloat in abundant literature in a spite of some recent reviews on certain specialized topics [4?6]. In consideration of this insufficiency, the present review intends to offer a comprehensive, critical review of the mechanical behavior of high-entropy alloys and some closely related topics.