CERAMIC (“FERRITE”) MAGNETS
Ferrite magnets are sintered permanent magnets consisting of fine powder Strontium or Barium. This powder is blended with a ceramic binder processed through a mold by compression or extrusion. They are brittle and hard by nature require specialized machining in the unmagnetized state and is not recommended for any structural application.
Manufacturing: Sintered or Injection Molded
Sintered- The magnets are pressed followed by sintering this unmagnetized magnet. The magnet can be wet or dry pressed. Wet pressing offers higher magnetic properties but yields poorer physical tolerances. Typically, for grades 1 and 5 are dry and wet for grade 8 or higher.
Injection Molded- The magnets are molded mixing Ferrite powder into a compound and then just like plastics processed by an injection molding machine. Injection Molded magnets produce complex shapes with tighter tolerances. The properties are the same or lower than the grade 1 Ferrite.
Most magnetic assemblies are fabricated by bonding the magnets with adhesives. They also can be fastened mechanically. Either process or combined will reasonably withstand the environmental impacts. Press fits are not recommended due to the brittle conditions of ferrite magnets.
Common Applications for FERRITE Magnets
Ferrite magnets are the most commonly and widely used in applications such as: arc shapes, motors, magnetic chucks/couplings, sensors, latches, speakers, badge holders, crafts, magnetic therapy, novelties, toys and much more.
|Grade||Br (Gauss)||Hc (Oersteds)||Hci (Oersteds)||BH max (MGOe)||Maximum Operating Temperature (°C)||Temperature Coefficient of Br (%/°C)||Density (Lb/in3)|
|Coefficient of Thermal||Expansion1||Curie||Temperature|
|(kg/m3 )||(lbs/in3)||(kg/m2)||(lbs/in2)||(kg/m2)||(lbs/in2)||// M||”´M||(°C)||(°F)|
|4.9 x 103||0.18||1.4 x 103||2.0 x 104||9.1 x 103||1.3 x 105||1 x 108||1.4 x 10-5||1 x 10-5||450||840|
// M Parallel to magnetic orientation
”´M Perpendicular to magnetic orientation