High-entropy approach starting from a corner of the phase diagram in designing high strength Fe-Mn-Co-based allow with good tensile ductility

The alloys without a base component (also called high-entropy alloys) with good mechanical properties can be obtained not only by compositional optimization starting from the equiatomic mixture but by dilution of the base component (Fe) in a commercial industrial steel by another transition metal. Low density Fe-Mn-Al-C system alloys containing up to 30 mass% of Mn and up to 10 mass% of Al is an excellent base system for utilizing the latter approach. In this article, we present a Fe-Mn-Co-Al-C alloy with good tensile plasticity of 10% and an extremely high yield and ultimate strength values up to 1590 and 1650 MPa, respectively, treated only by standard technological operations: homogenization, hot and cold rolling and annealing. This is achieved by exploring the high-entropy approach forming a duplex-type solid-solution structure without dispersion strengthening with carbide precipitates. Mechanical strengthening is a result of solid-solution hardening and deformation strengthening upon the applied thermomechanical treatments. This approach also can be applied to other various alloys.

Automated summary

In this study, a Fe-Mn-Co-Al-C alloy with good tensile plasticity and high strength was obtained through standard technological operations. The high-entropy approach was utilized to form a duplex-type solid-solution structure without relying on carbide precipitates for dispersion strengthening. This approach may be applicable to other various alloys.