Bonded thin cylinder magnets using Sm-Fe-N anisotropic powder

A cylindrical multipole oriented magnet is made from anisotropic SmFeN fine powder using injection molding. Unsaturated polyester resin serves as a binder instead of the conventional polyamide resin. The viscosity of the compound in a heated mold decreases quickly at first and increases with hardening. The lower the viscosity, the easier the compound penetrates thin areas in the mold and the easier it is for the magnetic field to orient the crystal axis. The shrinkage rate of unsaturated polyester resin can be controlled by additives.