Structural and Magnetic Properties of P Microalloyed Fe76Cu0.8Nb2.2B9Si12 Alloys

The development of Fe-based nanocrystalline alloys with high saturation magnetization (Bs), excellent magnetic softness and good manufacturability is highly desirable. Here, the effect of substituting 1 at% P for B and Si on the thermal stability, microstructure and magnetic properties of Fe76Cu0.8Nb2.2B9Si12 alloy has been studied in detail. It was found that replacing B with P effectively reduces the coercivity (Hc) of the alloy without deteriorating the Bs and permeability (μ). However, replacing Si with P has little effect on the Hc and Bs, yet significantly reduces the μ. The variation in the magnetic properties can be well understood from the evolution of the microstructure and magnetic anisotropy induced by P microalloying. The Fe76Cu0.8Nb2.2B8Si12P1 alloy with a good processing window, a high Bs of 1.41 T, a great μ of 29,000 at 1 kHz and a low Hc of 0.6 A/m is suitable for high-power electronic devices.