Magnetic properties of structure ordered cores composited with Fe_(78)Si_9B_(13) amorphous and pure iron powders

摘要

Composite cores of Fe_(78)Si_9B_(13) amorphous and pure iron powder were prepared by cold pressing. Effective permeability, initial permeability and the magnetic flux density of cores can all be improved by increasing the content of pure iron powder. With and without an external magnetic field, the circularly orientated (COCPC) and non-oriented (NOCPC) composite powder cores were obtained. The effect of the shape anisotropy of the flake powders on magnetic properties of the composite powder cores was investigated. All investigated magnetic properties of COCPC cores are better than those of NOCPC cores with the same mixture ratio and the effect of structural ordering weakens as the content of pure iron powder increases. For cores with only amorphous powder the effective permeability below 100 kHz, the initial permeability and the magnetic flux density for H_(max) = 8 kA m~(-1) of COCPC increase by 8.1,15 and 10 %, respectively, compared to those of the NOCPC. Pressing magnetic powders under an external magnetic field to form ordered structure is suitable for optimal design of soft magnetic cores toward practical applications.