Minor Cr alloyed Fe–Co–Ni–P–B high entropy bulk metallic glass with excellent mechanical properties

In this study, we propose a new strategy for designing ductile Fe-based bulk metallic glasses by minor substitution, which strengthens the local solute-centered atomic clusters and increases the concentration of free volume. The locally modified structure results in a stronger barrier to the formation and propagation of shear bands, which appears to be decisive for enhancing both yielding strength and plasticity. Accordingly, (Fe1/3Co1/3Ni1/3)77.5Cr2.5(P1/2B1/2)20 high entropy bulk metallic glass has been developed by minor substitution of (Fe–Co–Ni) in (Fe1/3Co1/3Ni1/3)80 (P1/2B1/2)20 by Cr. The compressive yielding strength increased by approximately 200 MPa and plasticity was enhanced from 4.4% to 11.2%. We believe that the proposed design strategy will provide a new method for improving the plasticity of Fe-based bulk metallic glass, and therefore, expand its applications in engineering.