LAUSR

Abstract Soft magnetic Fe-B-Si-C-Cu amorphous alloys were found to exhibit simultaneously high saturation magnetization above 1.7 T, low coercivity below 5 A/m, high permeability reaching 23100 at 1 kHz and 3500 at 1 MHz as well as high Vickers hardness above 1000 and good bending ductility. Similar good soft magnetic properties were also obtained in annealing-induced nanocluster + amorphous and nanocrystalline α-Fe + amorphous phases. The hardness increases rapidly to 1450 when a structure consisting of α-Fe + amorphous phases develops, and reaches 1820 for the α-Fe + Fe3(B,C) + Fe2B + amorphous phase mixture obtained just before the disappearance of amorphous phase. The ultimate high hardness is due to the high thermal stability of the finely mixed Fe3(B,C) and Fe2B phases caused by the addition of carbon. The present Fe-based amorphous alloys are useful for future developments of soft magnetic materials with good bending ductility as well as ultrahigh hardness.