Co-Fe-B-Si-Nb bulk glassy alloys with superhigh strength and extremely low magnetostriction

Co-based bulk glassy alloys with diameters up to 4 mm were formed in a [(Co1-xFex)(0.75)B0.2Si0.05](96)Nb-4 system. The bulk glassy alloys exhibit a superhigh fracture strength of 3980-4170 MPa and Young's modulus of 190-210 GPa. The bulk glassy alloys also exhibit excellent soft-magnetic properties, i.e., high saturation magnetization of 0.71-0.97 T, low coercive force of 0.7-1.8 A/m, high permeability of 1.48-3.25x10(4), and extremely low saturation magnetostriction of 0.55-5.76x10(-6). The first successful synthesis of the Co-Fe-B-Si-based bulk glassy alloys exhibiting superhigh fracture strength and excellent soft-magnetic properties with extremely low magnetostriction is encouraging for future development of Co-based bulk glassy alloys as new engineering and functional materials. (c) 2006 American Institute of Physics.