Biomagnetism ferrite magnet for matress, insole, massage mat

Factory sale small dis ferrite magnets Y25-Y35

Having obtained the ferrite, the cooled product is milled to particles smaller than 2um, sufficiently small that each particle consists of a single magnetic domain. Next the powder is pressed into a shape, dried, and re-sintered. The shaping may be performed in an external magnetic field, in order to achieve a preferred orientation of the particles.

Small and geometrically easy shapes may be produced with dry pressing also called Isotropic Ferrite Magnets. However, in such a process small particles may agglomerate and lead to poorer magnetic properties compared to the wet pressing process. Direct calcination and sintering without re-milling is possible as well but leads to poor magnetic properties.

characteristic 

The powder metallurgy method has low remanence and low recovery magnetic permeability. High coercivity, strong anti-demagnetization ability, especially suitable for dynamic working conditions of magnetic circuit structure. Hard and brittle material, can be used for emery tools for cutting processing. The main raw material is oxide, so it is not easily corroded. Operating temperature :-40℃ to +200℃. 

Ferrite magnets are divided into anisotropic (heterotropic) and isotropic (isotropic). The magnetic properties of the isotropic sintered ferrite materials are weak, but they can be magnetized in different directions of the magnet. Heteromorphic sintered ferrite Permanent Magnet materials have strong magnetic properties, but only along the intended direction of magnetization of the magnet. 

Physical property 

In the actual production of ferrite magnets, raw materials with good chemical composition may not be able to obtain ferrite magnets with good properties and microstructure sometimes, because of the influence of physical properties. The listed physical properties of iron oxide include mean particle size APS, specific surface area SSA, and loose density BD. As iron oxide accounts for about 70% in the formula of manganese zinc ferrite magnet, its APS value has a great influence on the APS value of ferrite magnet powder. Generally speaking, the APS value of iron oxide is small, and the APS value of ferrite magnet powder is also small, which is conducive to speeding up the speed of chemical reaction. However, the APS value should not be too small considering that the fine particle of powder is not conducive to post-process pressing and sintering easy crystallization. Obviously, when the APS value of iron oxide is too large, only the diffusion reaction of spinel phase can be carried out in the pre-firing process due to the large particle size, and the grain growth process can not be further carried out. This inevitably leads to the increase of activation energy required during sintering, which is not conducive to solid phase reaction. 

The main performance and grade parameters of sintered permanent magnet ferrite

 Ferrite Disk Magnets