Bonded neo powder is produced by processing specific combination of elements that result in distinct magnetic and physical characteristics. These powders are the primary material used in the manufacture of bonded rare earth permanent magnets, which, in turn, are used in motors and sensors utilized in a wide variety of products for consumer and industrial end markets. Neodymium metal, one of the rare earth elements, is the primary raw material in neo powder. It is alloyed with iron and boron, occasionally along with other elements in small quantities (such as cobalt). The alloy is melted and then rapidly solidified by melt spinning to produce neo powders with the desired characteristics for the manufacture of bonded neo magnets.
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Bonded neo magnets were first invented in 1982, and since that time they have been refined to a point where they now possess the highest magnetic strength of the four types of permanent magnets.
Production
Nd-Fe-B powder is combined with synthetic resin or polymer to form the bonded magnets. An important way of manufacturing these magnets is through the process of injection molding. The Nd-Fe-B alloy used for the production process is formed by a rapid quenching method. The hot molten Nd-Fe-B alloy is forced through a tiny nozzle unto a water cooling drum that is rotating at a very high speed to form thin crystalline Nd-Fe-B alloy ribbons that will be crushed into powder. The powder is further subjected to heat treatment to improve its coercive force and then mixed with the synthetic resin. The resulting mixture is kneaded, pelletized and then sent to the injection molding process. A mold which will form the desired shape of the magnet is first custom designed from a metal and the pellets are fed into the mold and melted at high pressure. Mechanical or hydraulic pressure is applied to the mixture so as to ensure that all cavities within the mold are filled. An external magnetic field (for anisotropic magnets) is also applied on the magnet during the injection molding process. It is then allowed to cool and removed with ejecting pins. Excess materials on the finished magnet is trimmed off and recycled. The finished magnet is inspected and packed up.
Applications of bonded neo powder
Bonded neo powder is incorporated into numerous end market applications that utilize bonded neo magnets. These products are primarily motors and sensors used in a range of products, including computer and office equipment (e.g., hard disk drives and optical disk drive motors and fax, copier and printer stepper motors), consumer electronics (e.g., personal video recorders and mp3 music players), automotive and industrial applications (e.g., instrument panel motors, seat motors and air bag sensors) and home ventilation systems (e.g., ceiling fans).