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)(77.5)Cr-2.5(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.

Automated summary

A new strategy of minor substitution has been proposed to enhance the plasticity and yielding strength of ductile Fe-based bulk metallic glasses. The locally modified structure leads to improved resistance to shear band formation and propagation, resulting in significant improvement in both properties. One example is the development of (Fe1/3Co1/3Ni1/3)(77.5)Cr-2.5(P1/2B1/2) 20 high entropy bulk metallic glass, which shows substantial enhancement in plasticity and yielding strength.