Effect of the substitution of Si for B on thermal stability, magnetic properties and corrosion resistance in novel Fe-rich amorphous soft magnetic alloy

Soft magnetic alloy Fe83.3SixB16-xCu0.7 (x = 0, 1, 2, 3 and 4) ribbons were produced by the single roller melt spinning method. The Si content dependence of magnetic properties and corrosion resistance was investigated. Appropriate addition of Si is effective to the improvement of thermal stability, soft magnetic properties and corrosion resistance in this alloy system. Excellent soft magnetic properties with low coercivity 3.1 A/m and high magnetic flux density 1.66 T can be obtained when x = 1 annealed at 365 degrees C for 10 min. Compared with the Sifree ribbon, the corrosion resistance of the x = 1 alloy ribbon is also improved. The X-ray photoelectron spectroscopy (XPS) indicates that the formation of an SiO2-enriched passive film is mainly responsible for the high corrosion resistance of Si-containing (x = 1) alloy in 3.5 wt% NaCl solution. Low cost of raw materials, high thermal stability, good soft magnetic properties as well as excellent corrosion resistance make this alloy a promising candidate for future application.