Influence of the corrosion on the saturation magnetic density of amorphous and nanocrystalline Fe73Nb3Si15.5B7.5Cu1 and Fe80Zr3.5Nb3.5B12Cu1 alloys

Amorphous FeMBCu (M = Nb, Zr) and FeNbSiBCu alloys with nanometer size crystallites have attracted attention due to their soft magnetic properties. The mechanism through which crystallization affects the corrosion and the comparative effect of corrosion on magnetic properties of FeMBCu (M = Nb, Zr) and FeNbSiBCu alloys has not yet been evaluated. In this paper the effect of partial crystallization on corrosion resistance of amorphous Fe 73 Nb 3 Si 15.5 B 7.5 -Cu 1 and Fe 80 Zr 3.5 Nb 3.5 B 12 Cu 1 alloy ribbons and the comparative effect of corrosion on saturation magnetic flux density, Bs, of these alloys were investigated. The samples were characterized by X-ray diffraction, differential scanning calorimetry and X-ray photoelectron spectroscopy. Corrosion resistance evaluation was carried out by measuring mass loss of samples immersed in 0.1 M H 2 SO 4 solution, and by measuring potentiodynamic polarization curves (potential vs. current). Saturation magnetic flux density, Bs, of the samples were measured. After partial crystallization of Fe 80 Zr 3.5 Nb 3.5 B 12 Cu 1 amorphous sample the corrosion resistance decreased, while for the Fe 73 Nb 3 Si 15.5 B 7.5 Cu 1 the corrosion resistance increased. The decrease of Bs after treatment in the corrosion solution as observed in the nanocrystalline Fe 80 Zr 3.5 Nb 3.5 B 12 Cu 1 sample was larger than that observed for both amorphous and the nanocrystalline Fe 73 Nb 3 Si 15.5 B 7.5 Cu 1 samples after the same treatment.