A kind of soft magnetic metal powder and preparation method thereof

Abstract

The invention discloses a soft magnetic metal powder and a preparation method thereof. Two kinds of gas atomized iron-nickel-molybdenum alloy powders with large particle size and carbonyl iron powder with small particle size are mixed to form the main body of the magnetic powder, and then binary pickling is performed, and acid washing is carried out. After washing, the powder is subjected to high-temperature composite phosphating treatment. After the powder is dried, the prepared coating slurry is mixed, stirred evenly, and then granulated. The obtained granules are baked at 70-90° C. for 60-80 minutes, and cooled to After mixing with lubricant at room temperature, sieving through 50-270 mesh to obtain soft magnetic metal powder. The powder prepared by the invention has the characteristics of high magnetic permeability and low loss, and the integrally formed inductor pressed by the powder has the advantages of low loss, low heat generation, high efficiency, low DC resistance, and cost saving of copper wire.

Description

technical field [0001] The invention belongs to the field of magnetic functional materials, in particular to a soft magnetic metal powder and a preparation method thereof. Background technique [0002] The development of wide bandgap semiconductor power devices and the improvement of high power density ceramic capacitor technology have promoted the development of filters and inductors in the direction of high efficiency, high power density and low loss. requirements, that is, higher inductance values, lower losses, and higher current can be used within the specification size range. The one-piece inductors are mostly made of metal powders that are coated with insulation and pressed with copper coils embedded in them. The core of the improvement of the characteristics of the one-piece inductors lies in the improvement of the characteristics of the soft magnetic metal powders used. [0003] Generally, carbonyl iron powder or iron-silicon-chromium alloy powder is often used as ...

AI Technical Summary

Problems solved by technology

[0003] Generally, carbonyl iron powder or iron-silicon-chromium alloy powder is often used as the original powder to make one-piece inductors. The advantages of carbonyl iron powder are good DC superposition characteristics, low powder hardness, and easy pressing and molding, but its magnetic permeability is low, making high inductance. When the value of the inductance is increased, the number of turns of the coil needs to be increased, resulting in large inductance size, high cost of copper wire, and low DC resistance R DC High; the advantages of FeSiCr alloy powder over carbonyl iron powder are good anti-rust properties and slightly higher magnetic permeability, but the powder has higher hardness and higher loss

In order to reduce powder loss, the Chinese patent with publication number CN113012886A mixes the FeSiBPCoC alloy powder obtained by atomization with fine soft magnetic powder iron-nickel, sendust, amorphous powder, etc., and the mixed powder The small particle size will inevitably lead to low magnetic permeability of the final powder, and the bulk loss of some materials in the mixed powder is high, so it is difficult to achieve the goal of low loss

The Chinese patent with the notification number CN110136910B discloses a high-permeability and low-loss iron-based soft magnetic composite material and its preparation method. Its core is to coat the reduced iron powder with insulation-treated carbonyl iron powder as the coating material. The reduced iron powder used in this method has high loss, and the carbonyl iron powder is difficult to evenly cover the surface of the reduced iron powder, so it is still difficult to achieve the purpose of high magnetic permeability and low loss

The Chinese patent with the notification number CN109545537B discloses a magnetic powder core and its preparation method. The process is phosphating and coating carbonyl iron powder, but the problem of low magnetic permeability caused by carbonyl iron powder still exists and has not been improved.

The Chinese patent with the publication number CN113724957A discloses a soft magnetic composite powder, a soft magnetic powder core and a preparation method thereof. The method is to coat the soft magnetic powder with magnesium oxide and an organic resin, but ignores the difference caused by the different types of powder. Different basic electromagnetic properties and different particle size ratios bring about different pressing effects. At the same time, the adhesion of the magnesium oxide coating layer is small, and it is still difficult to ensure the excellent point magnetic properties of the powder.