Enhancement of plasticity in Co-Nb-B ternary bulk metallic glasses with ultrahigh strength

► BMGs with critical diameters up to 2 mm were fabricated in CoNbB alloy system. ► The present alloy system possesses both σy of 4610-5340 MPa and εp up to 5%. ► The enhanced yield strength results from the increasing atom packing fraction. ► Enhancement of plasticity is ascribed to formation of nanoscale clusters in CoNbB BMGs.