Barium ferrite and strontium ferrite
Barium ferrite is a kind of permanent magnet ferrite with large dosage and wide application. The ideal component ratio is BaO.6Fe2O3(or BaFe12O19). The actual permanent magnet products are BaO.(5~6)Fe2O3, and the anisotropy constant is K13.3X105J/m3 at room temperature. The single-domain particles have good coercivity.
The ideal component ratio of strontium ferrite is SrO.6Fe2O3, and the actual production of permanent magnet product is SrO.(5~6)Fe2O3. The critical size of single domain is larger than that of barium ferrite, and the single domain is easily obtained during sintering. Br and Hcb are higher than barium ferrite, and are not easy to cause irreversible demagnetization at low temperature, so they are more suitable for the occasion of large demagnetization.
Bonded ferrite - rubber magnet
The ferrite powder is not mixed with rubber or plastic can be made into composite permanent magnet material bonding ferrite, can be molded or injection molding into a variety of high-precision complex shape components. Bonded ferrite is divided into soft bonding (rubber bonding) and hard bonding (plastic bonding). Soft bonding products are rubber magnets, which can be pressed into sheets or strips.
In addition to the mechanical properties of the bonded ferrite is easy to process, another advantage of it is that it can produce any size of magnetic energy product from the maximum to zero, and good temperature stability, corrosion resistance, high coercivity. Shape plasticity, low cost and wide range of performance make bonded ferrites become the fastest growing hot spot in the permanent magnet material market. The magnetic properties of bonded ferrites are usually lower than those of similar sintered ferrites because they are filled with a large number of non-magnetic binders with a volume of 10%~15%.
