The taw materials Magma uses to produce hard-ferrite magnetic, are Barium-Ferrite and Strontium-Ferrite .
These raw materials are easily (SrO.6 Fe203) and Strontium-Ferrite (Ba0.6 Fe203) available and therefore hand ferrite magnets offer the best value for money.
Anisotropic sintered ferrite permanent magnets are made by using ceramics technology, similar to the one used for making porcelain The powder is pressed under the influence of external magnetic field to determine the magnetic orientation of the powder grains.
Magma specializes in the production of anisotropic wet-pressed magnets. "Hard" magnets are characterized by high coercivity (Hcb, Hci), related to the remanence (Br).
Their magnetizing remains permanent, and stability is excellent. Being oxids, hard ferrites operate in a very tough environment, without the need of coating (the surface can however be coated, if extreme cleanliness is needed by the customer).
Hard ferrite's mechanical properties are like other ceramics. They are sensitive to mechanical impact. Machining is done mainly by diamond grinding.
Wet pressed anisotropic hard ferrites are now used extensively in the automotive industry, as rotors or stators in D.C. motors, in home appliance industry, as rotors for synchronous motors manufacturers and in the audio industry in loudspeakers, earphones and micromotors.
