Common magnetization directions of neodymium magnets: radial and axial

     Many people in the selection and use of Ndfeb will encounter a problem: need radial magnetization or axial magnetization, here we will discuss some magnet magnetization direction related issues.

1. Direction and source of magnetization

     The magnetization direction is the first step to obtain the magnetism of the custom NdFeB neodymium magnet, and it represents the north and south direction of the magnet. Neodymium magnets are not magnetic in the early stage of production, because the crystal structure of permanent magnets is easily magnetized, so it can be obtained under the interference of the outside world, the greater the effect of the external magnetic field, the higher the magnetic property of the magnet, and the magnetic field will remain after the disappearance of the external magnetic field.

2. Common magnetization direction

     General factory custom sintered NdFeb permanent magnets can be manufactured into block, disc, cylinder, ring, arc, spherical, etc. These are common and dominant types in the market, their magnetization direction is very simple, respectively, radial magnetization and axial magnetization. For radially magnetized neodymium magnets, the magnetic field is mainly distributed on the inner arc and outer arc, usually used in cylindrical, circular, arc magnets; For axially magnetized ndfeb magnets, the magnetic field is mainly in two end faces, usually used in block, cylinder, disc, ring and other magnets.

     In addition to the simple direction of magnetization, sintered NdFeb magnets can also be multi-pole magnetized according to the actual application needs, presenting multiple N pole and S pole on the same plane, but this situation will use a specially designed magnetizing fixture, the cost is quite expensive.

3. Magnetization process

     The basic principle of magnetization is to place the magnet that needs to be magnetized in the magnetic field of the magnetizer coil, where a direct current flows through it to apply a magnetic field to magnetize the magnet. If the magnetization field does not reach technical saturation, the remanent Bj and coercive Hcj of the permanent magnet will not reach their appropriate values. Sintered magnet is generally pressed by magnetic field oriented molding, so the direction of magnetization needs to be determined before production. Neodymium magnet, once made, cannot be changed direction, if the direction is wrong, it needs to be re-customized, which will greatly increase the production cost.