Excellent strength-ductility synergy and corrosion resistance in a metastable high entropy alloy via heterogeneous structure design

For metastable high entropy alloys (HEAs), the balance between mechanical properties and corrosion re-sistance is rarely achieved. Here, metastable HEAs with a heterogeneous structure (HS) were fabricated by innovatively combining cold rolling and partial recrystallization annealing, showing excellent corrosion resistance and strength-ductility synergy. HS exhibits heterogeneous distributions of dislocation density and grain size. Extraordinary strength-ductility is mediated by prominent hetero-deformation-induced strengthening, high-density dislocations, grain refinement, and transformation-induced plasticity. Such HS samples show higher corrosion resistance than the homogeneous coarse-grained sample, which is due to the low coincidence site lattice grain boundaries, substructures and the formation of stable passive films.(c) 2023 Elsevier B.V. All rights reserved.