According to the different production process, rare earth permanent magnetic material
(NdFeB-Nd2Fe14B): can be divided into the following three kinds.
1. Sintered NdFeB magnets
- sintered Nd-Fe-B permanent magnets are smelted by air grinding. The coercivity value is very high and the magnetic properties are very high. The maximum magnetic energy product (BHmax) of the sintered NdFeB magnets is more than 10 times higher than that of ferrite. Its own mechanical properties are also good enough to cut into different shapes and drilled holes. The maximum working temperature of high-performance NdFeB products can reach 200 degrees Celsius. Because the content of its material, NdFeB magnet is easy to corrosion, the different coating must be carried out according to different requirements. (such as galvanizing, nickel, environmental protection zinc, environmental protection nickel, nickel copper-nickel, environmental protection nickel copper-nickel and so on.) Neodymium magnets are very hard and brittle, with high demagnetization, high cost/performance ratio, not suitable for high working temperature (> 200 ℃).
2. Bonded NdFeB magnets
--- it is composite NdFeB permanent magnet, which is made of NdFeB powder and resin, plastics or low melting point metal, and then compacted, extruded or molded. Bonded NdFeB products are one-time formed, no secondary processing, can be directly made into a variety of complex shapes. Bonded NdFeB products have magnetism in all directions, can be processed into NdFeB compression mold and injection mold. High precision, excellent magnetic performance, good corrosion resistance, good temperature stability.
3. Injection NdFeB magnets
- with extremely high accuracy, it is easy to make anisotropic thin wall ring magnets or thin magnet with a complex shape