Superhigh strength and excellent soft-magnetic properties of [(Co1−xFex)0.75B0.2Si0.05]96Nb4 bulk glassy alloys

Bulk glassy alloys of [(Co1−xFex)0.75B0.2Si0.05]96Nb4 with diameters up to 4mm were synthesized in the composition range of x=0.1–0.4. In addition to high glass-forming ability, the bulk glassy alloys exhibit superhigh fracture strength of 3980–4170MPa and Young’s modulus of 190–210GPa, as well as excellent soft-magnetic properties, i.e., rather high saturation magnetization of 0.71–0.97T, low coercive force of 0.7–1.8A∕m, high permeability of (1.48–3.25)×104, and extremely low saturation magnetostriction of (0.55–5.76)×10−6. The mechanisms for the high glass-forming ability, superhigh strength, and excellent soft-magnetic properties of the Co-based bulk glassy alloys are discussed.