Catching Fe-based bulk metallic glass with combination of high glass forming ability, ultrahigh strength and good plasticity in Fe–Co–Nb–B system

The Fe-based quaternary bulk metallic glass with critical diameter up to 2.5 mm was pinpointed in Fe–Co–Nb–B system using a strategy for catching the best glass former based on relative glass forming ability of alloys. The best glass former Fe56.04Co13.45Nb5.5B25 exhibits glass transition temperature of 821 K, supercooled region of 58 K, compressive strength of about 4.5 GPa, Vickers hardness of about 13.7 GPa, and compressive plastic strain of about 0.6%. The combination of high glass forming ability, high thermal stability, ultrahigh strength and good plasticity makes this alloy of potential applications as a structural material.