What Are Bonded Magnets Anyway?
• Bonded magnets are composites of a permanent magnetic powder(s) embedded in a non‐magnetic matrix.
• The matrix is typically a thermoplastic or elastomeric binder.
• Common processing techniques are extrusion, injection molding, compression bonding, and calendering.
• Exhibit excellent mechanical properties compared to fully dense rare earth and ferrite magnets.
• End product has good finish and dimensional tolerances requiring no finishing operations.
• Injection molded magnets can be formed into complex shapes and be insert or over molded directly onto other components to produce assemblies.
• The non‐magnetic binder lowers the density of the magnet and dilutes the contribution of the magnetic powder.
• They generate less magnetic output per unit volume than fully dense magnets.
• The two most common magnetic powders are isotropic NdFeB and hard ferrite.