Cryo-pre-straining contributes to achieving high yield strength in high-entropy alloys

Abstract

In this study, we propose an effective and feasible strategy to significantly improve the room-temperature yield strength of the Co35Cr20Fe15Mn15Ni15 HEA by 338%, from 281 MPa (as-recrystallized, before CR) to 1231 MPa (30% CR) through cryo-pre-strain-inducing defects such as dislocations, stacking-faults (SFs), nano-twins, Lomer-Cottrell (L-C) locks, and HCP martensite, while maintaining good ductility (16.4% elongation in 30% CR). Additionally, the contribution of these defects to the yield strength enhancement was quantified. This study offers a new perspective for the preparation of advanced FCC high-entropy alloys.