Excellent strength-ductility synergy and corrosion resistance in a metastable high entropy alloy via heterogeneous structure design
Kejie Lu, Jiahao Li, Youfan Wang, Xinkai Ma
Abstract
For metastable high entropy alloys (HEAs), the balance between mechanical properties and corrosion resistance 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.