| Abstract Scope |
High-entropy alloys (HEAs) comprise multiple principal elements in near-equal amounts. They are scientifically interesting because theories that have been developed for dilute solid solutions cannot be directly applied to concentrated alloys lacking “solvents” and “solutes” in the traditional sense. Furthermore, a handful exhibit striking mechanical properties, for example, strength, ductility, and toughness that are simultaneously enhanced at cryogenic temperatures, unlike in conventional materials where they are traded off. In this talk, I will summarize what we have learned about the mechanical properties of this new class of alloys by focusing on a few model systems. While the basic mechanisms of plastic deformation in HEAs are broadly similar to those seen in conventional alloys, a common feature of HEAs with superior mechanical properties seems to be their ability to activate multiple strengthening mechanisms, often sequentially. As a result, the strain hardening regime is greatly extended and necking postponed. Based on these findings, further improvements in strength, without sacrificing ductility and toughness, can be envisioned in the vast compositional space occupied by HEAs. |