COMPARE AND CONTRAST
MAGNETIC APPLICATIONS AND MATERIALS

Attributes of Neodymium Material

  • Very high resistance to demagnetization
  • High energy for size
  • Good in ambient temperature
  • Moderately priced
  • Material is corrosive and should be coated for long term maximum energy output
  • Low working temperature for heat applications, but higher levels of heat resistance materials are being introduced periodically

Applications of Neodymium Magnets

  • Magnetic separators
  • Linear actuators
  • Microphone assemblies
  • Servo motors
  • DC motors (automotive starters)
  • Computer rigid disc drives, printers and speakers

Attributes of Ceramic Material
  • High intrinsic coercive force
  • Tooling is expensive
  • Least expensive material compared to alnico and rare earth magnets
  • Limited to simple shapes due to manufacturing process
  • Lower service temperature than alnico, greater than rare earth
  • Finishing requires diamond cutting or grinding wheel
  • Lower energy product than alnico and rare earth magnets
  • Most common grades of ceramic are 1, 5 and 8 (1-8 possible)
Applications of Ceramic Magnets
  • Speaker magnets
  • DC brushless motors
  • Magnetic Resonance Imaging (MRI)
  • Magnetos used on lawnmowers and outboard motors
  • DC permanent magnet motors (used in cars)
  • Separators (separate ferrous material from non-ferrous)
  • Used in magnetic assemblies designed for lifting, holding, retrieving and separating

Attributes of Samarium Cobalt Material
  • High resistance to demagnetization
  • High energy (magnetic strength is strong for its size)
  • Good temperature stability
  • Expensive material (cobalt is market price sensitive)
Applications of Samarium Cobalt Magnets
  • Computer disc drives
  • Sensors
  • Traveling wave tubes
  • Linear actuators
  • Satellite systems
  • Motors where temporary stability is vital

Attributes of Cast Alnico Material
  • Size parameters range from 1 ounce to about 70 pounds
  • Will cast to a variety of shapes and sizes

Attributes of Sintered Alnico Material

  • Size parameters range from about one ounce of material up to one cubic inch
  • Pressed to close tolerance/minimal grinding to finish
  • Mechanically strongest of alnico

Attributes of Both Cast and Sintered Alnico

  • Very temperature stable, great for high heat applications
  • Maximum working temperature 975° - 1020° F
    May be ground to size
  • Does not lend itself to conventional machining (hard and brittle)
  • High residual induction and energy product compared to ceramic material * Low coercive force compared to ceramic and rare earth materials (more subject to demagnetization)
  • Most common grades of alnico are 5 and 8
Applications of Alnico Magnets
  • Magnetos
  • Separators
  • Sensors
  • Electron tubes
  • Traveling wave tubes
  • Radar
  • Holding magnets
  • Coin acceptors
  • Clutches and bearings
  • Motors
  • Distributors
  • Relays
  • Controls
  • Generators
  • Receivers
  • Telephones
  • Microphones
  • Bell ringers
  • Guitar pickups
  • Loudspeakers
  • Security systems
  • Cow magnets


Questions to consider when choosing a Magnet...
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