Samarium Cobalt (SmCo) magnet
Samarium Cobalt rare-earth (SmCo) magnets are manufactured by using powder metallurgy techniques, which include stringent process controls and complicated heat treatment, cycles. This magnet is high performance and low temperature coefficient permanent magnet made of samarium, cobalt and other rare earth elements. The composition of this alloy is approximately 35% Samarium, 60% cobalt with the balance being Fe & Cu. As the second generation of Rare Earth permanent magnet, Sm Co not only has high energy ranging from 14 MGOe to 28 MGOe and reliable coercive force, but also exhibits the best temperature characteristics in Rare Earth material family. Including SmCo5 and Sm2Co17, an alloy compose of Samarium-Rare earth magnet, manufactured by powdered metallurgical process involving the sintering of powder under vacuum, commonly referred to as 1:5 and 2:17 materials. As rare earth magnet becomes one of the most advanced commercialized permanent magnet materials today, they are available in a number of different grades that span a wide range of properties and application requirements. The biggest advantage of sm co magnet is high working temperature (up to 300 ºC). Compared with NdFeB, it is more suitable for working under higher temperature. Sm Co magnet needn't to be coated because it is difficult to be eroded and oxidized.
Features of Samarium Cobalt Magnet:
Most excellent temperature characteristics in Rare-Earth magnet family; Limited raw material supply result SmCo5/Sm2Co17 high in cost. It is extremely hard and brittle, High demagnetization resistance, Outstanding thermal stability, Excellent anti-corrosion properties. Good corrosion resistance and no special surface treatment required, excellent for compact designs where high working temperature is a major concern. Grinding and slicing operations possible. Extremely resistant to demagnetization.
Applications:
SmCo magnet is suitable for machines with high magnetic requirements. Good for strict working environment requirement. It is widely used in various motors, Electronic magnetron, Magnetic Transmission, Magnetic Therapy, Magnistor, instruments, watches, sensors, detectors, radars, generators, radars and other high-tech equipment. Assemblies can be fabricated by adhering magnets with adhesives to suit a range of environments, by mechanically fastening magnets, or by a combination of these methods. Due to the relatively brittle nature of these magnet materials, press fits are not recommended.
Samarium Cobalt Machining:
Samarium Cobalt magnet rare earth material is very brittle and conventional machine tools and cutters are not appropriate. The brittle nature combined with the powder metal grain/crystal structure hampers the use of carbide tools. Electrostatic discharge machines (EDM), diamond tooling and some abrasives are the usual means of fabrication for this rare earth magnet alloy. Most magnet materials are machined in the un-magnetized state. Once the fabrication and cleaning operation are completed, the Sm Co magnet is then magnetized to saturation.
Magnetizing:
Samarium Cobalt rare earth magnets are extremely strong and they require a huge magnetizing field. Huge magnetizing fields require special equipment and aren't generally magnetized by customers. The anisotropic nature of sintered Sm Co magnets results in a single direction of magnetization. This direction must be observed when magnetizing and when integrating the magnet into the final assembly. Often times an indicator is used to identify a specific magnetic pole for the customer’s assembly process. This indicator can be a laser engraved mark or simple paint dot.