PRODUCTION METHOD OF A FERRITIC NI-ZN MATERIAL FOR MAGNETIC CORES

摘要

The invention refers to a production method of a ferritic Ni-Zn material for magnetic cores used within the frequency range of 1.5...30 MHz and intense magnetic fields containing 47.5...49.8% Fe2O3, 30...35% NiO, 13...17% ZnO, 0.5...1% CoO, 0.2...0.7% MnO4 molar percents and 0.2...1% in SiO2 weight, carrying the usual operations of dosage, mixing, pre-sintering, grinding, the atomisation of the ground powder, and pressing, characterized by the fact that, in order diminish losses within the frequency range of 1.5...30MHz, but at the same time, insure a permeability variation with very low temperature, the final heat treatment consists of an increased temperature from 600 degrees C to the maximum temperature of 1200...1260 degrees C with a minimum gradient of 4.2 degrees C/min. with a length of the maximum temperature level of 1...1.5 h, the cooling taking place at the maximum temperature of up to 600 degrees C, up to a minimum of 4.2 degrees C/min, and from 600 degrees C up to room temperature with a maximum gradient of 1 degree C/min. The technical characteristics of the optimal composed material are:μ1=110 +- 20%; tgδ/μ1 <= 100 x 10<-6> where f = 10 MHz, B1>= 370 ml