Maximizing ductility in non-equiatomic single phase FCC high entropy alloys

In this project, we develop two non-equiatomic FCC structued HEAs with different stacking fault energies (SFEs).

The designed Cr₁₀Mn₅₀Fe₂₀Co₁₀Ni₁₀ (at. %) HEA with high SFE shows a dislocation dominated deformation mechanism, whereas, in the Cr₁₀Mn₁₀Fe₆₀Co₁₀Ni₁₀ (at. %) HEA with low SFE, twinning-induced plasticity is the major deformation mode. We observe the breakthourgh of strength and ductility trade-off faciliated by dislcoation multiplication and microbands formation in the former alloy. The effects of grain size and SFEs on the tensile strength and ductility of the two HEAs were studied systematically. These insights are used to project some future directions for designing advanced HEAs through the adjustment of stacking fault energy by tuning the Mn content.