Three Common Production Processes For NdFeB Magnets

Three Common Production Processes for NdFeB Magnets

NdFeB magnets, a permanent magnet type, are characterized by extremely high coercive force (Hc), maximum magnetic energy product, and remanence (Br). They also offer excellent magnetic stability and are significantly lighter than ordinary magnets. As a result, their applications are extensive, covering nearly all industries.

In daily production, the price of NdFeB magnets varies based on their magnetic performance grade and the processing technology used. Generally, there are three main production processes for NdFeB magnets: the sintering process, bonding process, and injection molding process. Let's examine these processes in detail.

The sintered NdFeB magnet process involves grinding the magnetic material into powder using airflow and then smelting it in a furnace to form a material with specified specifications. NdFeB magnets produced by this process exhibit very high coercive force and a magnetic energy product that is more than ten times greater than that of ordinary ferrites. The price of NdFeB magnets made using this method is relatively standardized, with minimal variation. Once formed, the magnets can be cut into various shapes as required. However, their surface has relatively high chemical activity, so electroplating is necessary, with zinc-nickel plating being the most common.

Compared to sintered NdFeB magnets, the bonded NdFeB magnet process results in higher prices. This is primarily because bonded NdFeB magnets are integrally formed in a single operation, eliminating the need for additional cutting. In this process, NdFeB powder is mixed with other materials and shaped into permanent magnets using compression, extrusion, or injection molding techniques.

The injection molding NdFeB magnet process is the most demanding of the three. This technology requires highly precise molds, into which NdFeB powder is placed to produce finished products with complex shapes. The resulting products are often very thin, and the cost of NdFeB magnets made using this technology is the highest.