Production of Nanocrystalline (Fe, Co)-Si-B-P-Cu Alloy with Excellent Soft Magnetic Properties for Commercial Applications

With the aim of applying to a magnetic core material, the effect of ribbon thickness on the magnetic properties of a (Fe, Co)-Si-B-P-Cu alloy ribbon was investigated. It is found that the Si addition in (Fe, Co)-Si-B-P-Cu nanocrystalline alloy increased the saturation magnetic flux density (Bs), but degraded the coercivity (Hc), suggesting that the Si addition should be suppressed to a little amount. It is also found that the replacement of Fe with Co is quite effective for obtaining better magnetic properties of Fe-Si-B-P-Cu alloy. Even for the thicker ribbons exceeding 30μm in thickness, the nanocrystalline Fe81.2Co4Si0.5B9.5P4Cu0.8 alloy exhibited low Hc of 7A/m and high Bs of 1.84T. Such excellent magnetic properties were successfully reproduced in 50mm wide ribbons. This regards that the nanocrystallized Co-containing alloy has high applicability to high-efficiency magnetic core material. [doi:10.2320/matertrans.MBW201402]