Formation, ductile deformation behavior and soft-magnetic properties of (Fe,Co,Ni)–B–Si–Nb bulk glassy alloys

Fe-based [(Fe,Co,Ni)0.75B0.2Si0.05]96Nb4 bulk ferromagnetic glassy alloy rods with the diameters up to 4 mm were synthesized by copper mold casting. The addition of Ni element caused no decrease in glass-forming ability and fracture strength, but increased the compressive deformation ductility of this Fe-based bulk glassy alloy system. The glassy alloy rods exhibit super-high fracture strength over 4000 MPa, high Young's modulus over 200 GPa, elastic strain of 0.02 and plastic strain up to 0.005. The bulk glassy alloys also exhibit good soft-magnetic properties, i.e., high saturation magnetization of 0.8–1.1 T, low coercive force below 3 A/m, and high permeability of 1.6–2.1 × 104 at 1 kHz. The success of synthesizing a super-high strength Fe-based bulk glassy alloy with some compressive plastic strain and good soft-magnetic properties is encouraging for future development of Fe-based bulk glassy alloys as new engineering and functional materials.