Ferrite Magnets: The Various Shapes and Their Manufacturing Process

Ferrite magnets, also known as ceramic magnets, are a type of permanent magnet made from iron oxide (Fe2O3) combined with either barium carbonate (BaCO3) or strontium carbonate (SrCO3). These magnets are highly resistant to demagnetization and offer excellent stability over a wide range of temperatures. They are widely used in various applications such as electric motors, speakers, magnetic separators, and microwave devices. In this in-depth look, we will explore the various shapes of ferrite magnets and their manufacturing process.

Shapes of Ferrite Magnets:

Disc/Cylinder: These magnets are cylindrical or disc-shaped with a circular cross-section. They are commonly used in applications where rotational movement or magnetic field generation is required, such as motors and generators.

Ring: Ring-shaped ferrite magnets have a hollow center and are used in applications where they need to fit around a cylindrical object, such as sensors, speakers, and magnetic couplings.

Block/Rectangle: These magnets have a rectangular shape and are used in various applications, including magnetic separators, magnetic chucks, and magnetic assemblies.

Arc/Segment: Arc-shaped ferrite magnets have a curved surface and are often used in electric motors, generators, and loudspeakers to generate a specific magnetic field pattern.

Sphere: Ferrite magnets in the form of spheres or balls are used in magnetic toys, educational kits, and other applications where a round magnet shape is desired.

Manufacturing Process of Ferrite Magnets:

Raw Material Preparation: The manufacturing process of ferrite magnets starts with the preparation of raw materials. Iron oxide (Fe2O3), along with the chosen dopants (barium carbonate or strontium carbonate), is carefully measured and mixed in precise ratios. Other additives, such as binders, may also be added to enhance the magnet's properties.

Powder Milling: The mixed raw materials are then milled in a ball mill or attritor to reduce the particle size and ensure a homogeneous mixture. This step helps in achieving a fine and uniform distribution of the dopants throughout the iron oxide.

Forming: The milled powder is then mixed with a binder to form a slurry. This slurry is poured into molds of desired shapes, such as discs, rings, blocks, or arcs. The molds may be made of metal or other materials that can withstand high temperatures and pressure.

Pressing: The slurry-filled molds are subjected to a pressing process to remove excess moisture and achieve the desired density. The pressing can be done either by uniaxial pressing, where pressure is applied in one direction, or isostatic pressing, where pressure is applied from all directions. Uniaxial pressing is more commonly used for ferrite magnet manufacturing.

Sintering: The pressed magnets are then sintered in a high-temperature furnace. The sintering process involves heating the pressed magnets to temperatures typically ranging from 1,000 to 1,300 degrees Celsius (1,800 to 2,400 degrees Fahrenheit) in a controlled atmosphere. This process promotes the diffusion of atoms and the formation of a dense, solid magnet structure.

Machining and Finishing: After sintering, the magnets are cooled and removed from the furnace. They may undergo additional machining processes, such as grinding or slicing, to achieve the desired dimensions and tolerances. Surface treatment, such as coating or plating, may also be applied to protect the magnets from corrosion.

Magnetization: The final step in the manufacturing process is magnetization. The magnets are exposed to a strong magnetic field, either by passing an electric current through a coil or using permanent magnets, to align the magnetic domains within the material and create

Zhejiang Zhongke Magnetic Industry Co., Ltd. is a prominent ferrite magnet manufacturer based in China. With years of experience in the industry, the company has established itself as a leading supplier of high-quality ferrite magnets to domestic and international markets. We also manufacture type of neodymium magnet.