Ferrite magnets Manufacturers online

Ferrite magnets belong to the group of permanent magnets and consist of a mixture of iron oxide (Fe₂O₃) and ceramic materials, such as barium or strontium carbonate.

They were first developed in the 1930s and are widely used due to their special physical properties.

Below you will find an overview of the material composition, the magnetic properties, the mechanical properties, the special variants and the production of ferrite magnets, as well as an overview of their areas of application and their advantages:

Material composition of ferrite magnets:

Ferrite magnets consist of ceramic and metallic components:

1. Iron oxide (Fe₂O₃)
2. Barium carbonate (BaCO₃) or strontium carbonate (SrCO₃).

Magnetic properties of ferrite magnets:

Ferrite magnets are based on the principle of ferromagnetism:

1. Ferrite magnets have a crystal structure in which electron spin and orbital moments are aligned within specific domains (magnetic regions).
2. Ferrite magnets have a high coercivity, which means that they retain their magnetization even at high temperatures and external magnetic fields.

Mechanical properties of ferrite magnets:

1. Due to their ceramic base, ferrite magnets are resistant to rust.
2. They are stable at temperatures from -40 °C to around 250 °C.
3. They are cheaper than other magnet materials such as neodymium or samarium-cobalt.
4. Compared to neodymium magnets, ferrite magnets have a lower energy density and remanence.

Production of ferrite magnets:

1. Powders of iron oxide and a carbonate (strontium or barium) are mixed in a fixed ratio and finely crushed in mills.
2. Additives such as binders or plasticizers can be added to improve processability.
3. Compacting the powder by pressing (dry or wet), optionally with a magnetic field.
4. Heating and compacting at high temperatures (sintering) to form the crystal structure.
5. Grinding, cutting and magnetizing for the final shape and magnetization.

Special variants of ferrite magnets:

1. Anisotropic ferrite magnets: Higher magnetic force as the domains are aligned during pressing.
2. Isotropic ferrite magnets: Cheaper production, uniform magnetization in all directions.

Use of ferrite magnets:

Ferrite magnets are versatile, especially in applications where high corrosion resistance and low cost are critical:

1. Electronics:
Loudspeakers: ferrite magnets are a key component of loudspeaker systems as they can generate strong magnetic fields.
Transformers and inductors: Ferrite cores are used in transformers to efficiently conduct electromagnetic waves.
Microphones and sensors: They help convert sound or mechanical waves into electrical signals.

2. Industrial applications:
Motors: Ferrite magnets are found in direct current and alternating current motors.
Magnetic separators: They separate magnetic from non-magnetic materials in recycling and mining processes.
Magnetic couplings: Found in pumps and other applications where contactless power transmission is required.

3. Household appliances:
Household appliance motors: Washing machines, vacuum cleaners and other appliances use electric motors.
Refrigerator magnets: These use magnetic properties to attach notes or decorations to metallic surfaces.

4. Toys and teaching aids:
Magnetic building blocks: toys that contain ferrite magnets encourage creativity and technical understanding.
Teaching aids: To illustrate magnetic fields in physics experiments.

Advantages of ferrite magnets:

• Manufacture and materials are inexpensive, ideal for mass production.
• Stainless thanks to ceramic composition, no additional coating required.
• Stable at temperatures from -40 °C to around 250 °C.
• Lighter than many other types of magnets, e.g. neodymium magnets.
• Insensitive to many chemicals, including solvents.
• High coercivity prevents demagnetization in external fields.
• Versatility: Available in isotropic and anisotropic form for different requirements.

Ferrite magnets are indispensable components in many areas of technology and everyday life. Their excellent corrosion resistance and cost-effectiveness make them a popular choice for mass applications. However, their lower magnetic strength makes them less suitable for high-tech applications where high magnetic energy densities are required.

Here is an overview of the most important criteria to consider when buying ferrite magnets:

When purchasing ferrite magnets, it is important to know the specific requirements of your application in order to select the appropriate magnets.

• The intended use determines the magnetic properties:
• Magnetic strength (remanence, coercivity): Depends on the intended use, e.g. in loudspeakers or motors.
• Isotropic: Magnetization possible in all directions, but lower magnetic force.
• Anisotropic: Magnetically stronger, but can only be magnetized in one specified direction.
• Choose the right shape: Round (discs), rectangular (blocks), rings, segments or customized shapes.
• Pay attention to dimensional tolerances, especially for applications with precise fits.
• Check the operating temperature of your application. Ferrite magnets are stable at -40 °C to 250 °C, but there are differences depending on the manufacturer and alloy.
• Ferrite magnets are inherently corrosion resistant, but may require additional coating in humid environments or aggressive media.
• Ferrite magnets are fragile and require careful handling.
• Ensure that the load (e.g. pressure, impact) in your application is minimal or is compensated for by the housing.
• Clarify whether the magnet is supplied already magnetized or whether you need to magnetize it yourself.
• Select the correct magnetization direction: Axial (along the height) / Diametral (along the diameter)
• Consider the price per piece, especially for large quantities. Ferrite magnets are inexpensive, but bulk orders offer additional savings.
• Choose suppliers that perform quality checks and provide documentation (e.g. specification sheets, material certificates).
• Look for ISO certifications (e.g. ISO 9001) that indicate quality and reliability.
• If standard products are not sufficient, many manufacturers offer customized solutions.

By carefully evaluating these points, you can ensure that you get ferrite magnets that are optimally suited to your application.

Ferrite magnets can be purchased from various suppliers. Comprehensive information about manufacturers and suppliers of Ferrite magnets from all over the world can be found on Exportpages.