Manufacturing Process
1. Dry process:
By dry process, can produce isotropic & anisotropic magnets. The tool can be changed and developed easily.
2. Wet process:
By wet process, only anisotropic magnets can be produced. It is complicated to change the tool and the tooling charge is much higher.
Processing begins with granulation or drying of the ferrite powder raw material before axial pressing to form compacts of the required shape.
Isotropic hard ferrite magnets are produced by dry pressing of granulated ferrite raw material using mechanical or hydraulic presses.
Anisotropic magnet properties are achieved by pressing in a magnetic field. In this case, pressing may be carried out using dry powder or wet slurry dependent upon the level of anisotropic properties required.
Specially designed electromagnetic tools are employed to produce the anisotropic grades. With all pressing techniques, continuous in-process monitoring techniques ensure consistent green density is maintained on all products.
After pressing the compacts are sintered in air at high temperature to consolidate them, thereby giving their definitive shape and strength.
Grinding and/or other finishing operations can be used to achieve very close dimensional tolerances if necessary.
Components may be magnetized before final inspection, packing and despatch.