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Samarium-Cobalt Magnet



Samarium-cobalt magnets (SmCo5) are powerful magnets rare earth magnets composed of samarium and cobalt. These are brittle magnets and hence prone to crack and chipping. Samarium magnets can be used for high temperature applications.

Features
Following are the features of samarium cobalt magnets:
  • High magnetic properties
  • Good thermal stability
  • Resistance to corrosion
  • Resistant to demagnetization
Machining
The brittleness of cobalt has made it prone to chipping and cracking hence it should be protected from the same. The machining of the samarium cobalt should not be done using conventional methods. However using certain amount of coolants it can be abrasively ground. The use of coolant minimizes risk of heat fracturing. Moreover, the use of coolant also reduce the risk of fires caused by oxidized grinding dust.
Magnetization And Handling
Samarium magnets can cause fire if they are grounded in a dry condition because grinding dust has a low temperature ignition point. They can also pinch the skin if suddenly attracted to magnetic objects. Since these smco magnets can cause irreparable damage to the electrical appliance and computers they must be kept away from them.

Applications
The samarium magnets have following applications:
  • In servo motors
  • Pump couplings
  • Sensors
  • Applicable in high temperature
  • Traveling wave tubes
  • Satellite system
  • Linear actuators
  • Computer disc drive
  • Food processing industries
Process for making samarium cobalt magnets: Samarium-Cobalt Magnet
  • The first step involves the sintering of (smco )powder in a die.
  • The powder is then fused into a solid material.
  • Pressing are of two types die press and isostatic press. Isostatically pressed has higher magnetic properties than die press.
  • To meet final tolerance finish machining is accomplished.
Graphical Representation



Properties

Physical Properties of Samarium cobalt
Curie point 770°C(Approx)
Temperature 200°(Approx)
Density 8.5g/cm3
Hardness 50-60
Electrical Resistance 50Wcm
Temperature coefficient 0.016%


Magnetic Properties
SmCo 1-5 Alloys SmCo 2-17 Alloys
Curie temperature 750°C 825°C
Reversible temperature coefficient -.043%/ C -.03%/ C
Recoil permeability 1.05 1.05
Max. service temperature 250° C 300°C


Articles :: Samarium Cobalt Magnets: Power with Utility
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