A kind of preparation method of iron-silicon-aluminum soft magnetic alloy powder capable of self-passivation and insulation

Abstract

The present invention provides a method for preparing Fe-Si-Al soft magnetic alloy powder capable of self-passivation and insulation, that is, during the alloy smelting process, the element P is rapidly cooled and cast to obtain crystal materials; The element P migrates to the crystal interface and is enriched on the crystal surface; followed by ammonia decomposition and annealing, the trace amount of H in the atmosphere 2 O combines with element P on the surface of the powder to make the powder self-passivated to form a phosphating layer. The passivated sendust powder has good insulating properties. The self-insulation of the powder prepared by the method of the present invention does not require a phosphating process, and can be pressed directly by adding resin and lubricant, thereby avoiding environmental protection and safety problems caused by the phosphating process while reducing production costs. The sendust magnetic core produced by this powder has extremely low magnetic loss characteristics, high Bs value of the magnetic core, and excellent DC superposition characteristics; the molding pressure is reduced, and the life of the press and mold is extended.

Description

technical field [0001] The invention belongs to the field of magnetic materials, and in particular relates to a preparation method of self-passivating soft magnetic alloy powder. Background technique [0002] Metal powder core is a new type of soft magnetic material with special functions of magnetoelectric conversion, mainly including four series of iron powder core, sendust magnetic powder core, high flux magnetic powder core and molybdenum magnetic powder core. With the development of electronic components towards high frequency, miniaturization, high current and energy saving, the upstream industry has continuously put forward higher requirements on the quality and performance of metal soft magnetic powder cores such as magnetic loss and DC superposition characteristics. [0003] Sendust magnetic powder core is a metal soft magnetic powder core produced from an alloy powder containing 5.4% aluminum, 9.6% silicon, and the rest is iron. Sendust alloy is also called Sendus...

AI Technical Summary

Problems solved by technology

[0005] The FeSiAl soft magnetic alloy powder produced by the existing casting + ball milling method generally has the following deficiencies: 1. The passivation and insulation of the powder body is not good, resulting in high magnetic loss, poor DC superposition characteristics, and abnormal shape of the powder body. lead to molding difficulties

2. The traditional casting is broken, the grain size of the ball milling process is large, the powder making is difficult, and the power consumption is high

3. The traditional phosphating technology used in the production of magnetic powder cores by existing sendust powder, the phosphating layer is not controlled, which may easily lead to too thick phosphating layer, lattice oxidation distortion, and serious material fragmentation, which reduces the initial Permeability, magnetic loss increases with it