Probing the Respective Strengthening Mechanism of High-Entropy (CoCrFeNi/CoCrFeNiMn) and Single-principle-element (Cu-4Al) Alloys

The strengthening mechanism of high-entropy alloys (CoCrFeNi/CoCrFeNiMn) is investigated and compared with a single-principle-element alloy (Cu-4Al) with similar stacking fault energy. Hall-Petch effect dominates the strain hardening of both alloys during progressive grain refinement to the ultrafine regime. Moreover, the high density of Lomer-Cottrell locks offers unique and extra hardening to ultrafine-grained high-entropy alloys.