COMPARE AND CONTRAST MAGNETIC APPLICATIONS AND MATERIALS
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 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 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 Ceramic Material
- Least expensive material compared to alnico and rare earth magnets
- High intrinsic coercive force
- Available in simple shapes only 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)
- Grade 8 is the strongest ceramic material available
- Tooling can be expensive
Applications of Samarium Cobalt Magnets
- Computer disc drives
- Sensors
- Traveling wave tubes
- Linear actuators
- Satellite systems
- Motors where temporary stability is vital
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 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
Attributes of Cast Alnico
- Size parameters range from 1 ounce to about 70 pounds
- Will cast to a variety of shapes and sizes
Attributes of Sintered Alnico
- 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 alnicos
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 are 5 and 8
