Inert Gas Atomization of Neodymium-Iron-Boron Permanent Magnetic Materials

摘要

NdFeB melt-spun ribbons produced by melt spinning process are widely used as the bonded magnet in compression molding as well in metal injection molding (MIM). However its usage in metal injection molding requires higher loading. Spherical powders having similar magnetic properties as the melt-spun ribbon are preferable for metal injection molding. In the present work the NdFeB spherical powders were produced by inert gas atomization (IGA) and their magnetic properties were compared to that of commercially available melt-spun ribbon. The magnetic properties of the as-atomized powder varied with respect to their particle sizes due to the difference in cooling rate experienced by the melt during atomization. Annealing the as-atomized powder to 650℃ for 10 minutes was found to increase the magnetic properties of the powder. However these values are still low compared to the annealed melt-spun ribbons.