Enhanced Strength-ductility of FeMnNiCo High-entropy Alloy with Incorporation of In-situ TiC Reinforcements

To further enhance the properties of high-entropy alloy (HEAs) and enable its potential applications, we employed a combination approach involving ball milling and induction melting to fabricate in-situ TiC reinforced composites within the FeMnNiCo high entropy alloy matrix. The effect of TiC content on the microstructure and mechanical properties of the composites were studied. It was observed that in-situ formed TiC did not induce any phase transition, maintaining the FCC structure of the high-entropy alloy matrix. As the volume fraction of TiC increased, both the number and size of TiC particles increased, leading to agglomeration in morphology. By introducing 5 vol% of TiC in the composites, a significant enhancement in ultimate tensile strength (609.2 MPa) and yield strength (349.1 MPa), corresponding to a respective increase by 32% and 46% compared to the matrix, was achieved; meanwhile, an elongation value as high as 45% was obtained. This combination of exceptional tensile strength and good plasticity is attributed to synergistic effects from orowan mechanism and solid solution strengthening.