Ferrite magnets are used in a variety of applications. Everyone can understand this in various ways, and they are frequently seen in a variety of vehicles. The main applications of such magnets, however, are in two areas. The first is soft ferrite, and the second is permanent ferrite. These two aspects' content and application are discussed further below.
Ferrite magnets can be widely used in the manufacture of permanent magnet starter motors, permanent magnet motors, permanent magnet concentrators, permanent magnet suspension heads, magnetic thrust bearings, magnetic separators, speakers, microwave devices, magnetic therapy tablets, hearing aids and other equipment.
There are two types of permanent ferrites: barium ferrite and strontium ferrite. They have high resistivity and belong to the semiconductor category. Therefore, the eddy current consumption is small, the coercive force is large, and it can be effectively used in the magnetic circuit of the large gap. It is used as a permanent magnet for small generators and electric ideas. Because it does not contain precious metals such as nickel, cobalt, etc., the source of raw materials is terrific. The process is not complicated, the cost is low, and it can replace AlNiCo permanent magnets.
Compared with the large magnetic energy product (B+H) m being low, it is larger than a metal magnet under equivalent magnetic energy. However, it is worth noting that its stability is poor, the texture is brittle, fragile, not resistant to charge sensation, and it is not suitable for measuring instruments and magnetic devices with detailed requirements.
This type of magnet is generally composed of several parts: single-component or multi-component ferrites such as manganese ferrite, zinc ferrite, nickel-zinc ferrite, and manganese-magnesium-zinc ferrite.
It has a much higher permeability at high frequencies than magnetic metal materials (including iron-nickel alloys, aluminium-silicon-iron alloys). It is suitable for working at frequencies from several kilohertz to several hundred megahertz. The saturation magnetic flux density Bs of ferrite is low, usually only 1/3 to 1/5 of iron.
The low magnetic energy stored in the unit volume of ferrite limits its use in the low frequency, strong current and high power band boundaries that require higher magnetic energy density. Processing ferrite belongs to the usual ceramic process, so the process is simple, and a large amount of precious metals is saved, and the cost is low. It is more suitable for use in high frequency, low power, and weak current scenes.
Nickel-zinc ferrite magnets can be used as antenna rods and intermediate-frequency transformer cores in radios. Manganese-zinc ferrites can be used as line transmission transformer cores in TV receivers. In addition, soft ferrites are also used in the magnetic centres of intensifiers and filters in communication lines. In recent years have also been used as high-frequency magnetic recording transducers (magnetic heads).