Strong ceramic magnets are widely applied in our lives. It is a metal oxide with magnet properties. What is the preparation technology of strong ceramic magnets? Let's take a look!
1. Weighing and mixing of strong ceramic magnets
The raw materials of ceramic magnet include main raw materials, additives and fluxes. Fe2O3, BaCO3, SrCO3 and CaCO3 are the main raw materials of ferrite. The weighing process needs to strictly follow the formula, otherwise the ideal magnetic performance cannot be obtained. The raw materials of the strong ceramic magnets are weighed and mixed in special equipment. The uniformity of the components is based on the mixing process. There are many factors that affect the uniformity of the mixture components.
2. Granulation of strong ceramic magnets
In order to ensure the smooth progress of the solid-phase reaction process, it is necessary to granulate the mixture before pre-sintering. During the granulation process, the solution will be sprayed into the mixture, and the particle size of the pellet material has an effect on the pre-sintering time.
3. Pre-sintering of strong ceramic magnets
The purpose of pre-sintering is to fully ensure the solid-phase reaction of the raw materials. After pre-sintering, most of the raw materials will be transformed into ferrite phase. The pre-sintering process will also improve deformation, shrinkage and density. The pre-sintered powder can be used as a raw material for sintered magnets, bonded magnets and wave-absorbing materials. Now most manufacturers of strong ceramic magnets directly purchase the pre-sintered powder.
4. Ball milling of strong ceramic magnets
In this step, the pre-sintered material will be pulverized into fine powder. The crushing process will be completed by ball mill equipment, and the grinding mediums are steel balls and water.
5. Molding of strong ceramic magnets
Based on the traditional classification method, strong ceramic magnets are divided into isotropic and anisotropic types. The molding methods of ceramic magnets are also divided into wet and dry methods. The molding process technology is highly intensive.
6. Sintering of strong ceramic magnets
Like other types of sintered magnets, the sintering step is also very important for ceramic magnets. First, the sintering process will affect the microstructure of the ceramic magnet, which in turn affects the magnetic properties of the magnet. Unreasonable sintering parameters will cause cracks, bubbles and deformation of the magnet.
7. Machining of strong ceramic magnets
The processing methods of strong ceramic magnets include grinding, polishing, cutting and punching. It should be noticed that the magnet manufacturers will use grinding wheels in the cutting step because the ferrite is an insulating material.