Applications of softmagnetic nanocrystalline VITROPERM^TM-alloys

Abstract
Nanocrystalline alloys are a new class of soft magnetic materials supplementing the existing spectrum with high permeabilities. The reliability of the production processes by rapidly quenching techniques, low cost raw materials and the consequences of zero magnetostriction make VITROPERM^TM (Fe_73,5Cu₁Nb₃Si_15,5B₇) the most prominent representative of these new alloys. The combination of a saturation value of 1.2 Tesla, permeabilities variable over a wide range between 20,000 and roughly 200,000, lowest eddy current losses up to high frequencies, the pronounced linearity of the flat hysteresis loop and the high thermal stability make VITROPERM^TM equal or superior to pemalloys, ferrites or amorphous cobalt based alloys in a wide field of applications. The paper summarizes the most important advantages of nanocrystalline magnetic cores in transfomers for pulse-current sensitive earth leakage circuit breakers, current transformers with small errors in phase angle and amplitude, common mode rfi chokes for EMC and KW power transformers.