What types of permanent magnet materials are there?

There are many types of permanent magnet materials with wide uses. They have mainly gone through three stages of application and development: metal permanent magnet materials, ferrite permanent magnet materials and rare earth permanent magnet materials.

Metal permanent magnet material

The metal permanent magnet material stage has earlier development and application. It is an alloy type permanent magnet material with iron and iron group elements as important components. It is also called permanent magnet alloy and mainly includes AlNiCo and FeCr. Cobalt type 2 permanent magnet alloy. Metal permanent magnet materials are prepared through a casting process, also called cast permanent magnet materials. With the discovery of high-performance rare earth permanent magnet materials in the early 1970s, the application of metal permanent magnet materials has been greatly impacted and gradually replaced by new permanent magnet materials. Currently, they are only used in niche special fields.

②Ferrite permanent magnet material

In the 1930s, people discovered ferrite permanent magnet material, which was invented by Philips Company in the 1940s. Because of its cheap raw materials, simple process and low price, it developed rapidly in the 1970s and its output ranked first. To this day, although ferrite magnets have low comprehensive magnetic properties, they have high resistivity, good stability, strong resistance to environmental changes, rich sources of raw materials, high cost performance, mature and simple processes, and no oxidation problems, so they are used in magnets. It is widely used in mid-to-low-end products with lower magnetic capability requirements. Ferrite permanent magnet material is also called permanent magnet ferrite. It is made of strontium oxide or barium oxide and iron oxide as raw materials. It is pre-fired, crushed, ball milled, powdered, molded, sintered, and mechanically processed through ceramic technology. manufactured. In other words, ferrimagnetism means that the magnetic moments of certain iron ions are antiparallel to each other and have permanent magnetic properties.