Fe-Si-Al alloy is an alloy powder of 85% Fe, 9% Si and 6% Al, which is processed by special process and pressed into ring or E-type magnetic powder cores. It is commonly called Kool M_ u magnetic powder cores or Sendust magnetic powder cores in the market.
Because of its high hardness and resistivity, Fe-Si-Al alloy is suitable for use as head material for video recording. The high hardness guarantees that the magnetic head has a longer service life and better image recording and playback quality. The high resistivity makes it have a higher permeability than other magnetic alloys at high frequencies.
And the thin sheet of Fe-Si-Al alloy sample is very brittle, it is impossible to winding the measuring coil directly on the sample. It is necessary to use insulating materials such as PMMA for sample protection box. When the coil is wound on the protective box with the sample, the gap flux will be introduced into the measurement results. Usually in the testing of high permeability alloys, because the permeability of the sample is much larger than that of the air, the contribution of the void flux is relatively small and can be neglected. However, the permeability of Fe-Si-Al alloy is not very high at high frequency, so the void flux must be corrected.