The raw materials used in magnet manufacturing are mined from the earth. Rare earth elements such as neodymium and samarium are extracted through complex mining operations and refined into pure forms before use. Once the raw materials are sourced, the manufacturing process can begin. It generally starts with a carefully calculated mixture of the primary metals, which are melted together in a vacuum or inert gas environment to prevent oxidation. The resulting alloy is cooled into ingots or ribbons, depending on the desired end product.

Next, the solidified material is crushed into a fine powder. This powder is then processed using various pressing techniques to align the magnetic domains. In the case of sintered magnets like neodymium and samarium cobalt, the powder is pressed into molds under high pressure, often in the presence of a magnetic field to orient the magnetic particles in the same direction. This directional pressing is critical for maximizing the magnet’s strength. The resulting compact is then subjected to sintering, a process that involves heating the material below its melting point to fuse the particles together and form a solid magnet. Sintering must be done in a controlled atmosphere to prevent oxidation and preserve the magnet’s magnetic properties.

After sintering, the magnets are cooled and undergo further mechanical processing. These steps include cutting, grinding, andMetal Separation   shaping the magnets to meet precise dimensional specifications. Because magnets can be brittle, especially rare earth types, this machining must be done carefully using diamond-coated tools or wire cutting techniques. Any damage or structural weakness introduced during this phase could significantly impair the magnet’s performance. Once shaped, the magnets are subjected to heat treatment processes to further enhance their magnetic characteristics and structural stability.

Following the shaping and treatment phase, magnets are often coated with a protective layer to prevent corrosion and mechanical wear. Neodymium magnets, for instance, are highly susceptible to oxidation and typically receive coatings of nickel, zinc, or epoxy resin. These coatings not only protect the magnet but also make it easier to handle and integrate into devices. The coating process can involve electroplating, spray coating, or dipping, and is selected based on the final application of the magnet.

Magnetization is the final critical step in the manufacturing process. This involves exposing the finished magnet to a strong external magnetic field, which aligns the magnetic domains within the material and gives the magnet its permanent magnetic field. The strength and direction of this magnetizing field depend on the type of magnet and its intended application. For example, some magnets are magnetized through thickness, while others may be magnetized across diameters or in multi-pole configurations for use in motors or sensors.