IQS Newsroom Articles on Ceramic Magnets
Ceramic Magnets
Ceramic magnets, or ferrite magnets, are the most common magnet used in industrial
applications. As permanent magnets, ceramic magnets have a much stronger magnetic
force than most other common magnets, and their non-metallic ceramic composition
makes them the most affordable magnet capable of industrial strength magnetic
force. As their name implies, ceramic magnets are a sintered composite of powdered
iron oxide, strontium (or barium) and ceramic powder; the finished product
is a brittle and porous charcoal gray ceramic. As with powdered metal parts,
ceramic magnets can be compacted into blocks, discs and arcs while in powdered
form. Once the magnet is sintered, however, machining and forming can be difficult
and costly; due to their brittleness and hardness, diamond cutters are usually
required to machine ceramic magnets.
Although the magnetic force of ceramic magnets is ranked slightly below alnico
magnets (a metallic magnet composited from aluminum, nickel and cobalt) and
much lower than rare
earth magnets, ceramic magnets are prized not only for their cost economy but
also for their magnetic permanence. A magnet's ability to retain its
magnetism under corrosion, vibration, exposure to electrical fields, time and
heat is important because it determines for which applications a magnet may be used. Ceramic magnets have excellent magnetic permanence under corrosion and
electrical exposure, making them the perfect material for DC motors, speakers
and lifting, retrieving and separating corrosive materials.
Ceramic magnets' magnetic permanence is beneficial in the welding and
construction industries as well as other motor, sound and electromagnetic environments
subject to vibration and electricity, but their thermal stability is very poor.
Applications which require industrial-strength magnets to operate under high
heat use either alnico magnets, which maintain magnetic permanence at up to
550 degrees Celsius, or samarium cobalt rare earth magnets, which also have
excellent high heat resistance.
Used in a myriad of industrial and commercial applications, ceramic magnets
are found in many home appliances, automobiles, children's toys, tools
and equipment at the doctor's office. Ceramic magnets are often found
in refrigerator magnet hooks, and they are notably stronger than other refrigerator
sheet magnets' poly-magnetic compounds. Because of their brittle, porous composition,
ceramic magnets are often nickel coated to prevent chipping and breaking.