Hetero-deformation induced strengthening, precipitation hardening, and metastability engineering in a novel maraging Fe68Ni10Mn10Co10Ti1.5Si0.5 medium entropy alloy

In the present study, the concept of maraging characteristics has been manipulated using a multistep thermomechanical approach involving isothermal aging and reversion treatments. Accordingly, a novel metastable maraging Fe68Ni10Mn10Co10Ti1.5Si0.5 (at%) medium entropy alloy has been designed and microstructurally engineered to achieve a heterogeneous medium entropy alloy decorated by (NiMn)3_xTix and n-Ni3Ti nanoprecipitates. Remarkably, the alloy exhibited an ultra-high yield strength of -1.3 GPa with a total elongation of -25.3% in the partially reversed sample, attributed to several aspects of microstructural heterogeneities, including the dual-phase microstructure, compositional gradient heterogeneity, and nano-precipitates. We proposed a prospective direction for the development of high-performance materials for structural applications through the microstructural engineering of Fe-based medium entropy alloy.