Samarium Cobalt magnets: good thermal stability, resistant to corrosion, resistant to demagnetization
Machining & Magnetization
Advantages:
Extremely resistant to demagnetization
high temperature stability (max operating temperatures between 250
°C (523
K) and 550
°C (823
K); Curie temperatures from 700
°C (973
K) to 800
°C (1,070
K)
Expensive and subject to price fluctuations (cobalt is market price sensitive)
Disadvantages:
Samarium cobalt magnets can easily chip; eye protection must be worn when handling them.Allowing magnets to snap together can cause the magnets to shatter, which can cause a potential hazard.Samarium-cobalt is manufactured by a process called sintering, and as with all sintered materials, inherent cracks are very possible. These magnets do not have mechanical integrity; instead the magnet must be utilized for its magnetic functions and other mechanical systems must be designed to provide the mechanical reliability of the system.
Comparison between neodymium and samarium cobalt
Manufacturing Methods
Compression Bonded - this is a technique whereby a special form of SmCo powder is blended with a plastic carrier material, die pressed and then heated. Parts made in this way can be of complex shapes and come off the tool with close tolerances, requiring no further finish machining. They have lower energy products than sintered materials - currently in the range of 15 MGOe.