The characteristics of nanocrystalline magnetic core materials are introduced1

The characteristics of nanocrystalline magnetic core

On the one hand, it can isolate eddy current, and the material is suitable for higher frequencies; on the other hand, due to the gap effect between particles, the material has low magnetic permeability and constant magnetic permeability; and because of the small particle size, basically no skin phenomenon occurs, The change of magnetic permeability with frequency is relatively stable; moreover, the powder core can be prepared into special-shaped parts of various shapes, which are used in different fields; finally, the industrially damaged strip can be crushed into magnetic powder, and then made into magnetic powder Core, which can reduce losses and increase the use value of materials. The magnetic and electrical properties of the magnetic powder core mainly depend on the magnetic permeability of the powder material, the size and shape of the powder, the filling factor, the content of the insulating medium, the molding pressure and the heat treatment process, etc. In the future, the soft magnetic powder core will still be along the lines of high Bs, high μ, high Tc and low Pc. The magnetic powder core is a kind of soft magnetic material formed by mixing and pressing ferromagnetic powder particles and insulating medium. Since the ferromagnetic particles are very small (0.55 μm used at high frequencies and separated by non-magnetic electrical insulating film substances. Low Hc and high frequency, miniaturization, and thinning are developed to meet the increasing thinning and thinning of magnetic components. Miniaturization, even the trend of integration.

Characteristics and Application of Nanocrystalline Magnetic Core

High magnetic permeability, nanocrystalline Fe73.5Cu1Nb3Si13.5B9 alloy has high saturation magnetic induction. The characteristics of good stability, and the material becomes brittle after heat treatment, easy to process into alloy powder. A new type of ultramicrocrystalline magnetic powder core may be made by using the alloy powder. Compared with the nanocrystalline magnetic core made of tape wound, the magnetic permeability of the nanocrystalline magnetic powder core is still very low, and the soft magnetic property is unstable. At present, there are problems that need to be solved urgently: 1. Effectively control the growth of nanocrystals during heat treatment; 2. The forming problem of magnetic powder core; 3. The influence of heat treatment specifications on the soft magnetic properties of magnetic powder core.

Application field of nano magnetic core

Noise is the main source of circuit interference in many power electronic equipment. It is necessary to use various filter devices to reduce noise, and the magnetic powder core is the main component of the differential mode inductance, and the filter plays a key role. In order to obtain a better filtering effect, the magnetic powder core material is required to have the following performance characteristics: high saturation magnetic induction, wide constant magnetic permeability, good frequency characteristics, good AC and DC superposition characteristics and low loss characteristics. In response to the above requirements, soft magnetic materials for inductors such as iron powder cores, notched amorphous alloy cores, and iron-nickel-aluminum powder cores (MPP powder cores) have been developed successively. These materials have played their respective advantages and advantages under different application conditions. effect. At present, UP powder cores occupy a major share in the high-end market. However, due to the complicated manufacturing process of M powder cores and the high price of raw materials, the price of powder cores remains high, and the scope of application is restricted to a certain extent. In recent years, iron-based nanocrystalline soft magnetic powder cores have attracted much attention because of their low price, simple preparation process, and excellent performance. The research on them is quite active. It is expected to replace the local use of UP powder cores and be applied in the high-frequency field. .