Effect of primary α-Fe on soft magnetic properties of FeCuNbSiB amorphous/nanocrystalline alloy

The effect of primary α-Fe precipitation on thermal properties and magnetic properties was systematically investigated by fabricating Fe_76.5-xCu₁Nb_xSi_13.5B₉ (x=0, 1, 2 and 3) amorphous/nanocrystalline ribbons using melt-spinning method at different cool rate, which is controlled by wheel linear speed. It was found that the rapid quenching process shows similar influence on α-Fe precipitation to heat treatment. The as-spun amorphous/nanocrystalline ribbons obtained at 20 m/s show low coercivity of 2.7 A/m and saturated magnetization of 1.25 T, and could be further improved to 1.54 T and 0.95 A/m, respectively, through component optimization and heat treatment. The results render that proper precipitation of primary α-Fe is a simple and efficient way for fabricating amorphous/nanocrystalline alloys with good magnetic properties.