Enhancement of strength–ductility combination and corrosion resistance behaviour in (FeCoNiCr)₉₂Ti3.5Al4.5 high-entropy alloy

The effects of thermo-mechanical treatment on the mechanical properties and corrosion resistance behaviour of the (FeCoNiCr) 92 Ti 3.5 Al 4.5 (at.-%) high-entropy alloy (HEA) were studied. Compared with the untreated specimen, the yield and ultimate tensile strength increased by 227.5% and 129.4% after thermo-mechanical treatment, with ductility remaining almost constant. The results indicated that the grain size refined from 233.44 to 2.31 μm, and the dislocation density considerably increased from 2.69 × 10 12 to 1.23 × 10 14 . Notably, after thermo-mechanical treatment, the formation of precipitates can narrow the passivation zone, thus increasing the tendency of pitting corrosion. The corrosion current decreased and the radius of the impedance curve increased, indicating the corrosion resistance behaviour improved, which was attributed to the grain refinement.