Permanent magnets will be magnetizing prior to use for their intended application in most cases. Permanent magnet will be magnetized when apply a magnetic field via its orientation direction and then achieved technical saturation with the increased external magnetic field. Different kind of permanent magnetic material needs different magnetic field to fulfill technical saturation. Remanence Br and intrinsic coercivity Hcj will be less than its due values when external magnetic field strength cannot reach the technical saturation magnetic field.
How to Magnetize Permanent Magnet?
Permanent magnet can be magnetized by both direct current magnetization and impulse magnetization. Direct current system includes direct current power and electromagnet or magnetizing yoke. Direct current magnetic field will generate once direct current entered the coil. Magnetic field strength between two poles of the electromagnet is proportional to the coil turns N and current intensity I, and inversely proportional to the gap between two poles of the electromagnet. Both electromagnet and magnetizing yoke are extremely difficult to magnetize high-coercivity permanent magnet to technical saturation. For impulse magnetization, the capacitor will be charged after rectification, then the electrical energy in capacitor instantaneous discharge to the magnetizing coil. Magnetizing coil will generate the pulsed magnetic field during the instantaneous strong current through it. Therefore, permanent magnet in coil will be magnetized.
Magnetizing Patterns of Permanent Magnet