Development and Application of Low-Noise 6.5% Si–Fe Sheet

Abstract

The effects of composition, magnetic annealing and texture on the magnetic properties, magnetostriction, and core noise of pilot-produced 6.5% Si–Fe sheet and transformer cores have been studied and the results compared with the core-loss and core-noise characteristics of domain-oriented 2V-CoFe and cube-textured 3% Si–Fe transformer cores. The application of magnetic annealing reduced magnetostriction of 6.5% Si–Fe sheet to 1×10−6 at 18 kG. The use of a low-magnetostriction core material, such as 6.5% Si–Fe, was shown to result in a considerable reduction in transformer core noise, reducing in turn the maximum noise level of a 3-phase, 400-Hz, 1250-VA static inverter to 50 dB in an acoustic frequency range of 0.4–20 kHz.

Potential of powder metallurgical methods to fabricate Fe-6.5Si soft magnetic components

“…2 Additionally, the alloy shows high specific electrical resistance of ρ el = 82 µΩcm 3 compared to iron with ρ el ∼ 10 µΩcm, high mechanical strength, and low noise due to neglectable magnetostriction. 4 However, its application was impeded due to its poor workability as an effect of the formation of ordered phases. Up to now, all fabrication processes are limited to the lab scale apart from the only commercially available Fe-6.5 wt.% Si thin sheet material JNEX, produced by JFE Steels.…”