Superior strength-ductility synergy of FeMnCrNiAlSi high entropy alloy with heterogeneous structures

Alloys with excellent strength-ductility synergy and cost-effective performance have always been the pursuit of materials for engineering applications. In this study, Fe 40 Mn 20 Cr 10 Ni 20 Al 5 Si 5 (at%) dual-phase high-entropy alloy with tensile strength of 1060 MPa and elongation of 26 % was developed. The precipitated Ni(Al, Mn) B2 phase was selected to strengthen the alloy, and the combination of soft and hard phases provides a strong work-hardening capability. The dual heterogeneous structure, consisting of partially recrystallized and precipitated phases, overcomes the strength and plasticity trade-off at room temperature. For the heterogeneous structures, the mixing law is applied to calculate the flow stress, revealing additional strengthening components from dislocation hardening, precipitation hardening , and back-stress hardening. Our results demonstrate the possibility of synergistic enhancement of mutually exclusive properties such as strength-plasticity of alloys through nano-precipitation and heterostructures , providing new insights into the preparation of high-strength and high-plasticity alloys. • A novel Co-free FeMnCrNiAlSi high entropy alloy was designed. • The Fe 40 Mn 20 Cr 10 Ni 20 Al 5 Si 5 alloy with heterogeneous structure is composed of B2 and FCC phases. The composition of B2 phase is Ni(Al, Mn). • The Fe 40 Mn 20 Cr 10 Ni 20 Al 5 Si 5 alloy with heterogeneous structure possesses tensile strength of 1060 MPa and elongation of 26 %.