Ferrite, or ceramic, magnets are the most used magnets. Ferrite magnets are affordably priced and have high corrosion-resistance. In addition to this, the applications of ferrite magnets are very broad.
Ferrite magnets have a maximum energy product of up to around 4.3 MGOe. Ferrite is the least expensive magnetic material and is highly corrosion-resistant. This means that no coating is required. Ferrite magnets can be produced to be either isotropic and anisotropic with the maximum application temperature of 225 °C.
Developed in the 1950s, ferrite is comparable to AlNiCo magnets in terms of magnetic strength. It is a chemical compound consisting of a ceramic material with iron oxide (Fe2O3) doped with strontium.
Because the material is ceramic, it does not rust, and it can be used without coating in nearly all applications. Ferrite magnets have a wide range of applications such as;
- Microwave ovens
- Magnetic filters
- Pump drives
- Measuring equipment
- Reed switches
- Motors and generators
The advantages of ferrite magnets include the fact that they are inexpensive, yet strong with ferrite being the least expensive of the commercial magnetic materials. However, it offers a good balance between strength and affordability. In addition to this, it can be magnetized with multiple poles and it does not easily demagnetize.
On the other hand, ferrite has some disadvantages. These include the fact that the material properties degrade linearly with increasing temperature. It is a hard, brittle material, so it breaks easily, and it is much weaker than the rare-earth magnets. Ferrite has about one-seventh the tensile strength of a similarly sized neodymium magnet.
The technical details of ferrite are as follows:
- Density: 5000 kg/m³ ((0.180 lbs./in³);
- Magnetic field required for saturation: ±10 kOe;
- Solid sintered ferrite magnets can be pressed wet or dry;
- BHmax value of the available range of neodymium grades: 6-36 kJ/m³.