Speaker
Description
A cost-effective, Co-free Fe-based medium entropy alloy (MEA), was developed to achieve an exceptional combination of strength and ductility at both room and cryogenic temperatures. The Co-free design is strategically motivated by the high cost, supply risk, and density associated with Co-containing alloys, making the present system more economically and industrially viable without compromising performance. The alloy design prioritizes higher concentrations of low-cost elements (Fe, Mn, Si, and Al) while limiting expensive constituents, enabling a sustainable pathway for advanced structural materials. Thermodynamic phase calculations is used for the development of a predominantly face-centered cubic (FCC) matrix with precipitate formation, promoting multiple deformation mechanisms. The alloy was synthesized via vacuum casting followed by homogenisation, forging and hot rolling to obtain a refined microstructure. The compositional design, with higher Fe content, enables the activation of transformation-induced plasticity (TRIP) and twinning-induced plasticity (TWIP), contributing to enhanced strain hardening and mechanical stability. The developed MEA exhibits superior strength–ductility synergy compared to conventionally processed hot-rolled 316L stainless steel and representative Co-containing medium and high entropy alloy. Notably, the alloy demonstrates improved tensile performance at both ambient and cryogenic temperatures, highlighting its suitability for demanding applications under cryogenic environments.