Effect of Cu Element Addition on Soft Magnetic Properties of Fe-Gd-B Alloys

In order to conduct a systematic study on the influence of the copper element on the soft magnetic properties of alloys, a series of alloy ribbons with compositions of Fe90.70−xGd2.32B6.98Cux (x = 0.25, 0.5, 0.75, 1.0, 1.25, and 1.5) were fabricated via the single-roller melt-spinning method. The microstructure and magnetic properties of these ribbons were systematically characterized using X-ray diffraction (XRD), differential scanning calorimetry (DSC), and vibrating sample magnetometry (VSM). The research findings indicate that the introduction of the copper element significantly enhances the soft magnetic properties of the alloys. For the alloy ribbon with the optimized composition of Fe89.95Gd3.32B6.98Cu0.75, the saturation magnetization (Bs) attains 1.74 T. The improvement in performance is primarily attributed to the precipitation of the nanocrystalline α-Fe phase. This phase features fine grain sizes and relatively wide magnetic domain structures, which contribute to an increase in the saturation magnetization and a reduction in the coercivity, thus comprehensively optimizing the soft magnetic properties of the alloys.