The invention discloses an iron-
nickel metal magnetic powder core with high stable magnetic
conductivity and low loss and a preparation method of the iron-
nickel metal magnetic powder core. The iron-
nickel metal magnetic powder core is prepared through the steps of preparing iron-
nickel alloy powder through gas atomization, screening the particle size, carrying out insulation
coating, carrying out
compression molding, carrying out heat treatment and carrying out impregnation and spraying. Wherein in the insulating
coating process, a
passivation solution is adopted to form an insulating layer on the surface of the iron-
nickel alloy powder, and the
passivation solution comprises 0.1 wt%-0.3 wt% of
phosphoric acid, 0.1 wt%-0.6 wt% of
sol and the balance deionized water according to the weight part of the iron-
nickel alloy powder; and the pH value of the
passivation solution is 4-7. According to the technical scheme, the iron-nickel
alloy powder is subjected to insulation
coating through cooperation of the
phosphoric acid, the
sol and the coating agent, the
magnetic hysteresis loss is effectively reduced, the magnetic
conductivity of the iron-nickel magnetic powder core is improved, the quality factor of the iron-nickel magnetic powder core is remarkably improved to 95 or above, and after the obtained high-magnetic-
conductivity low-loss iron-nickel magnetic powder core is subjected to long-term high-temperature aging, the magnetic conductivity change rate does not exceed 2%; and the safety and the performance stability are greatly improved in the application of power electronic devices.