Enhancement of crystal-orientation degree for plastic bonded strontium ferrite magnet

摘要

There have been developed various hard ferrite powders with a high magnetocrystalline anisotropy which are very useful for the bonded ferrite magnets. However, the conventional bonded hard ferrite magnets have not given the most of their intrinsic anisotropy. In this study, strontium ferrite (SrO·6Fe{sub}2O{sub}3) plastic bonded magnet was fabricated by the powder injection molding method using a metal mold in which the closed magnetic circuit may induce. The pellet was manufactured by heating strontium ferrite powder having small specific area. From the observation of crystal-orientation of the obtained specimens, it was proved that the anisotropic magnetic field induced from the closed magnetic circuit in the metal mold directly attributed to the improvement of coercive force of the plastic bonded strontium ferrite magnet. Further, the mechanism of enhancement of crystal-orientation degree was discussed.