Tunability of the mechanical properties of (Fe50Mn27Ni10Cr13)100-xMox high-entropy alloys via secondary phase control

The single-phase face-centered cubic (fcc)-structured Fe50Mn27Ni10Cr13 high entropy alloy (HEA) exhibits good ductility but low strength, which presents a challenge. By Mo-alloying and thermomechanical treatments, we have designed the (Fe50Mn27Ni10Cr13)(100-x)Mo-x (x = 0-6 at.%) alloy series with a wide range of mechanical properties. The careful control of secondary phases introduced in the cold-rolled and annealed (Fe50Mn27Ni10Cr13)Mo-2 sample resulted in an enhanced tensile strength from 250 MPa to 665 MPa, still having similar to 25 % ductility. TEM investigations of this alloy revealed the presence of deformation twins, dislocation cells, and ordered bcc nano-particles embedded in the ductile fcc matrix post-deformation. The observed deformation structures are an indication of successful cooperation between deformation twinning and precipitation strengthening in enhancing the tensile strength at maintained ductility compared to its cast counterpart. This work provides insight into the tunability of the mechanical properties of non-equiatomic HEAs via alloying and thermomechanical processing. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

By Mo alloying and thermomechanical treatments, a series of (Fe50Mn27Ni10Cr13)Mo-x alloys have been successfully designed, with significantly enhanced tensile strength while maintaining close to 25% ductility. TEM investigations revealed the presence of deformation twins, dislocation cells, and ordered bcc nano-particles in the alloy.