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Model cores based on amorphous SA1 and HB1 alloys for pole transformers were prepared and their audible noise was measured in terms of A-weighted sound power level in a hemi-anechoic chamber in accordance with ISO 3744 standard. The two amorphous cores annealed under optimum conditions to minimize the audible noise showed the same sound power level of 56 dB as M3 core at their typical operating flux densities. It was found that A-weighted sound power levels increased above 1.4 T for SA1 core and above 1.5 T for HB1 core. This provides design limitations for transformer cores based on amorphous alloys. Index Terms--Amorphous magnetic materials, audible noise, audible noise measurement, transformer core.

Soft magnetic properties of block cores comprising Febal.Cu1Mo0.2Si4B14 nanocrystalline alloy ribbons (HBN core) were investigated. The HBN core shows a magnetic flux density at 2000 A/m (B2000) of 1.73 T, which is about 0.2 T higher than that of the core comprising Fe-based amorphous alloy ribbons (Fe-AM core). The core loss at 200 mT and 10 kHz is 8.5 W/kg, two thirds of that of the Fe-AM core. The coefficient of the excess eddy current loss for the HBN core is one half of that of the Fe-AM core; the difference in core loss is prominent at higher frequencies. [ABSTRACT FROM PUBLISHER]

Presents a study that investigated harmonics generation in metallic glasses. Analysis of the perminvar characteristics of the samples; Correlation between harmonic voltages and exciting field; Examination of the perminvarlike properties of magnetorestrictive cobalt-based glassy metals.

Examines the perminvarlike properties of glassy metal alloys with near-zero magnetorestriction. Effect of annealing temperature on direct current B-H loop of a glassy alloy; Types of B-H loops; Magnetic properties of glassy metal alloys.

Soft magnetic properties of magnetic cores assembled with Fe81.8Cu1.0Mo0.2Si4B14 nanocrystalline alloy ribbon are discussed. The nanocrystalline alloy ribbon was cast in an amorphous phase by a melt quenching method, and a nanocrystalline phase was obtained by high-heating rate annealing. A medium-size toroidal core assembled with this nanocrystalline alloy ribbon exhibits magnetic flux density $B_{{{800}}}$ at 800 A/m of 1.74 T, core loss $P_{{{16/50}}}$ at 50 Hz, and at 1.5 T of 0.29 W/kg. A racetrack-shaped core, which includes curved and straight sections in the same core, exhibits core losses at 1.0 T and at 400 Hz and 1 kHz of 1.5 and 5 W/kg, respectively. These core losses are as low as those of Fe-based amorphous alloys. A medium-size toroidal core assembled with this nanocrystalline alloy ribbon, secondarily annealed under a perpendicular magnetic field, exhibits core loss $P_{{{2/10k}}} at 0.2 T and at 10 kHz of 2 W/kg. This value of core loss is one of the lowest values for the metallic magnetic cores, which have a saturation induction Bs higher than 1.5 T. A core assembled with this material can be used in several applications from low to medium frequency ranges. Since this material exhibits a higher Bs and one half of the saturation magnetostriction \lambda \texts of Fe-based amorphous alloys with comparable core losses, the most possible applications are in such applications as distribution transformers and inductors in power electronics. [ABSTRACT FROM AUTHOR]