Sintered NdFeB magnets, the third generation of rare earth permanent magnet, are composed of Neodymium, Iron, Boron and a few transition metals. They have high remanence,high coercive force, high energy product, and high performance /cost. Currently Sintered NdFeB magnets are the strongest magnets available in the world.
Manufacturing Process
Neodymium, Iron, Boron and a few transition metals will be made into the NdFeB powder, then fine NdFeB powder will be compacted in a die and sintered, fusing thepowder into a solid material. Thereare 2 forms of pressing: die pressing and
isostatic pressing. Sintered parts normally need some finish machining in order to meet final tolerances.
Machining & Tolerance
Generally, Sintered NdFeB magnets must be machined using diamond-grinding techniques.Sometimes, machining operations may be performed on Sintered NdFeBmaterials using carbide tools, but surface finishes thus obtained may be less than optimal.The Standard tolerances for Sintered NdFeBmagnets are +/- 0.1mm for ground dimensions, but sticter tolerances are possible if specially required.
Surface treatments
The corrosion resistance of Sintered NdFeB magnets is considered poor. Surface coatingor plating is therefore highly recommended for Sintered NdFeB magnets. All kinds of surface coating are available, like Nickel, Zn, Ni-Cu-Ni, Gold, Silver, Sn, Chrome. We also applied special surface protection to Sintered NdFeB magnets, like ABS coating, Rubber coating, PTFE(Telfon) coating, stainless steel case, etc.
Magnetizing & Packing
Sintered NdFeB magnets require extremely high magnetizing fields, and can be magnetized in any direction as long as it is aligned properly. In some instances multiple pole magnetization is possible with special fixtures.All Sintered NdFeB magnets are anisotropic, and can only be magnetized in the orientation direction,
so particular consideration must be given to this when designing complex assemblies, if it is intended to magnetize after assembly.
Sintered NdFeB magnets are mechanically weak, and magnetically very strong. They should be packed properly in order to help user to use and handle them.
