The process for manufacturing ferrite magnets, also known as ceramic magnets, is not as costly or sophisticated as producing rare-earth neodymium magnets.
The chemical compound of ferrite magnets is SrO-6 (Fe2O3), a combination of strontium carbonate and iron oxide. Due to their chemical make-up it means they are extremely resistant to demagnetisation through heat and corrosion, although, like neodymium magnets they are very hard and brittle.
Step 1 – Calcination
The production of ferrite magnets begins with calcining a finely powdered mixture of iron oxide and strontium carbonate to produce a metallic-oxide material. In some grades, other chemicals such as cobalt and lanthanum are added to improve the magnetic performance.
Once cooled, the already fine powder is then milled a number of times reducing the calcined material to fine small particles that each particle consists of one single magnetic domain
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Step 2 – Pressed
The powder is then pressed and compacted into a die and sintered. If the process of shaping and pressing takes place within an externally applied magnetic field the particles forming the magnet will be aligned and the magnet produced will be anisotropic.
For this to be achieved the particles would first need to be mixed with water to form a slurry material.
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Step 3 – Sintered
Once pressed, the compacted particles are then sintered at very high temperatures to make the particles fuse together and make one single magnet and then magnetised to saturation.
Ferrite magnets are magnetised fairly easy and don’t require a large external magnetising field.
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Step 4 – Coating (Machining if needed first)
If the magnet requires machining then it will be machined using diamond coated machining tools and then coated or plated with the chosen coating.
Finally, every magnet sold by FIRST4MAGNETS is quality assured before it is dispatched to the customer to be used in hundreds of different applications.
If you have any questions or queries then be sure to get in touch with our team of experts who are available on 0845 519 4701 or sales@magnetexpert.com and are always happy to help.