The development of Neodymium Iron Boron, NdFeB, magnets has opened up a new era of magnetic design. The sintered NdFeB group of magnets have outstanding magnetic properties, high flux density, high coercivity, and super high energy products, which allow compact designs or miniaturization of existing designs. Previously large and heavy components could now be miniaturized by using these materials, and often resulting in cost savings for the overall assembly.
Neodymium-Iron-Boron magnet is produced by compacting a finely milled Nd2 Fe14B alloy powder in the presence of an electromagnetic alignment field. Magnets produced in the manner are anisotropic, and will exhibit a preferred direction of orientation when magnetized. The compacted parts are sintered and heat treated in a controlled inert gas atmosphere to achieve full density and optimize the magnetic properties. Final shaping of the magnet is accomplished by grinding with diamond abrasives.
Systems International Group supplies a variety of sintered neodymium magnets with energy products 30 – 48 MGOe, intrinsic coercive force 12K – 20K Oersteds, working temperature 80 º C – 180 º C (175 º F -350 º F). The NdFeB magnets we supplied is patent products and licensed by Sumitomo and General Motors.
Below are some of the grades of magnets we can offer our customers:
Note: Materials with energy product as high as 42MGOe are also available, please contact us directly for special grades.
Unlike most other magnet materials, NdFeB magnets are highly susceptible to oxidation. Effective coating systems have been developed to coat this type magnet and therefore allow them to be used in many applications. Systems International offers customers different coating options: nickel plating, zinc plating, epoxy resin with electrophoresis coating processing, or both applied.
The sintered NdFeB magnets require extremely high magnetizing fields. It requires fields of more than 40 KOe in order to be saturated. This is not common to produce and large power supplies in conjunction with carefully designed magnetizing fixtures must be used. A special consideration must be given to this when designing complex assemblies if it is intended to magnetize after assembly.
Mechanical clamping or epoxy adhering are the most popular methods of fastening NdFeB magnets to an assembly. Due to their brittle nature, press-fit is not recommended.
WARNING: Due to their extremely high magnetic strength and brittle nature, NdFeB magnet parts must be handled very carefully to prevent injury to personnel and damage to the magnets. Receiving and assembly personnel must be pre-warned about the dangers of handling these magnet parts.