Preparation And Properties Of Magnetic Powder Cores Of Nanocrystalline Alloys By Super-Gravity Field Percolation Process

Nanocrystalline alloys have excellent soft magnetic properties,with theirs as raw materials of nanocrystalline alloys magnetic powder cores as important inductance circuit components are also concerned.In this paper,different magnetic powder cores with high mechanical strength were prepared by super-gravity field percolation process,the effects of powder particle size ratio,super-gravity field coefficient,insulating agent concentration,and composite other magnetic powder on the properties of nanocrystalline alloys magnetic powder cores are investigated.The appropriate particle size ratio can improve the magnetic properties of the magnetic powder cores,and the optimal particle size ratio is 60 wt%100～200 mesh powder,20 wt%200～400 mesh powder,20 wt%400～1000 mesh powder.The effective permeability of the core at 3000 k Hz is 28.2,B_m=20 m T,and the loss at f=500 k Hz is 99.1 W/kg;reducing the concentration of the insulating agent is beneficial to improve the effective permeability of the magnetic powder cores with single granularity,when the mass ratio of epoxy resin to acetone is 1:1,the magnetic properties of the core are better,and the effective permeability increases by 26.3%,but the loss increases by 10.4%;the super-gravity field coefficient has little effect on the magnetic properties of the magnetic powder cores with single granularity,and the optimal value is 1000～3000.Directly adding amorphous powder obtained by air flow milling method is not conducive to the magnetic properties of nanocrystalline alloys magnetic powder cores with single granularity.For the magnetic powder cores with amorphous powder,the loss of the magnetic powder cores increases significantly,and the effective permeability increases first and then decreases with the increase of the additive amount.When a small amount of nano-Fe₃O₄ is added into the magnetic powder of nanocrystalline alloys,the properties of the magnetic powder will change drastically.Substituting 3 wt%nano-Fe₃O₄ for partial the 400～1000 mesh nanocrystalline powder in the optimal particle size ratio,the effective permeability of the magnetic powder core at3000 k Hz is increased by 1.1%,but the loss at 20 m T/500 k Hz is increased by 39.0%.In addition,the mechanism of preparation of nanocrystalline alloys magnetic powder cores by super-gravity field percolation process is also explored,and the influence of the percolation behavior of epoxy resin on properties is investigated,which provides a new idea for the preparation of high-performance nanocrystalline alloys magnetic powder cores.