Surface insulation treating method adopting boric acid as reactant to reduce sendust core loss

Abstract

The invention relates to a surface insulation treating method adopting boric acid as a reactant to reduce sendust core loss and belongs to the technical field of magnetic material preparation. The method comprises the following steps that 1, sendust is placed into a boric acid water solution to carry out high-energy ball milling so that the surface of the sendust can be fully moistened by the boric acid water solution; 2, the moistened sendust is dried for 1 h in a vacuum drying box with the temperature of 120 DEG C to be dehydrated; 3, the dehydrated sendust is placed into a reaction furnace with the temperature of 900 DEG C for 10-minute heat preserving, and cooled along with the furnace, and a multiphase insulating coating layer containing Al2O3, SiO2 and the like is synthesized on the surface of the sendust through a one-step reaction; 4, deionized water is used for cleaning the sendust having subjected to the boric reaction, and drying is carried out after cleaning; 5, 1wt% of epoxy resin and 0.8wt% of magnesium stearate are added to enable the sendust to be pressed into a magnetic powder core in a cold mode under 2000 Mpa; 6, the sendust core is annealed for 1 h at the temperature of 660 DEG C. The method is simple in process and low in cost; the prepared product is high in magnetic conductivity, low in loss and wide in application range.

Description

technical field [0001] The invention relates to a surface insulation treatment method for sendust magnetic powder core loss, in particular to a surface insulation treatment method for reducing sendust magnetic powder core loss based on boric acid as a reactant, and belongs to the technical field of magnetic material preparation. Background technique [0002] The magnetic powder core is a kind of soft magnetic material made by mixing and pressing magnetic material powder and insulating medium. Because its resistivity is much larger than that of alloys, the eddy current loss is small and can be used at higher frequencies. And because of its high saturation magnetization, it can also be used at higher power. These characteristics make the magnetic powder core have advantages that other magnetic materials cannot match in many applications. At present, it has been widely used in inductance filters, choke coils and switching power supply cores in telecommunications, radar, televi...

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Problems solved by technology

Chinese patent CN201210443610.X discloses a preparation process of a high magnetic flux density and low core loss sendust magnetic powder core. The target is obtained through steps such as powder selection, pretreatment, passivation treatment, insulation coating treatment, compression molding, and heat treatment. The prepared product has high magnetic permeability and low core loss, but the steps are relatively complicated