Sintered Ferrite Magnets
Sintered ferrite magnets, otherwise referred as ceramic because of their production process, are the least expensive class of permanent magnet materials.
The raw materials of ferrite magnets are mixed in the correct proportions, granulated, and calcined (pre-sintered). After going through several intermediate phases, a hexaferrite phase (BaFe12O19 or SrFe12O19) is achieved. The presintered granulate is ground to a powder. It can then be pressed wet or dry in a magnetic field (anisotropic) or in the absence of a magnetic field (isotropic) and sintered. The nature of the manufacturing process results in ferrite magnets that frequently contains imperfections such as cracks, porosity, chips, etc. Fortunately, these imperfections rarely interfere with a magnetâs performance. Maximum operating temperature of sintered ferrite magnets can arrive 250 â.