Tailoring microstructure with spatial heterogeneity in CoCrFeMnNi high-entropy alloy via laser surface relaxation

The face-centered cubic single-phase CoCrFeMnNi equi-atomic HEA has excellent mechanical properties in a wide temperature range, from cryogenic to room temperature. However, the low yield strength at room tem-perature limits its application as a structural material. Herein, we propose a novel heterostructuring method named laser surface relaxation (LSR) as a strategy to overcome the strength-ductility dilemma. Unlike conven-tional heterostructuring methods, the LSR method can freely tune the microstructure with spatial heterogeneity. The LSR-treated CoCrFeMnNi HEA exhibited exceptional mechanical properties with a synergetic strengthening effect.