| Abstract Scope |
FeMnAlC alloys have been studied for decades due to their outstanding strength–ductility combinations, reduced density, and potential for automotive and aerospace applications. However, key challenges remain in understanding processing, microstructure, mechanical properties, and manufacturability in these complex multi-principal systems. In this study, a series of Medium- and High-Entropy FeMnAlC-based alloys were designed using CALPHAD-based frameworks. A broad processing window of thermo-mechanical treatments were explored to evaluate microstructures and property combinations and relationships. The alloys exhibit single- and dual-phase microstructures containing nano- and micro-scale Kappa-carbides, along with TWIP/TRIP deformation mechanisms, enabling high strength, ductility, and density reductions relative to conventional steels. The influence of multi-element alloying on phase stability, microstructure, and properties was analyzed to assess how high-entropy and multi-principal alloy design concepts can be translated into next-generation steels. |