Introduction Of Samarium Cobalt Magnets

Samarium cobalt magnet(SmCo), also called samarium cobalt permanent magnet, is a powerful permanent magnet made of two basic elements, samarium and cobalt. Like NdFeB, it also belongs to the category of rare earth magnets. At present, there are mainly two components of SmCo₅ and Sm₂Co₁₇.

 

The strong magnetic ratio of SmCo and NdFeB, although the magnetic force is not so strong, but SmCo has two obvious advantages, namely higher temperature range and better corrosion resistance. Therefore, they offer the best value when comparing performance and size in high temperature environments or applications.

 

History

Samarium cobalt magnets, introduced in the 1970s, were the first commercially available rare earth magnets. Their introduction was revolutionary, tripling the maximum energy product of any other magnet at the time. Before the introduction of SmCo magnets, the standard in magnetism was the Alnico alloy magnet. It wasn't until increasing production costs led engineers to look for cheaper alternatives that neodymium magnets were developed and are now the strongest magnets in the world.

 

Advantages

SmCo Magnets are not as powerful as super strong neodymium magnets, but they have some significant advantages, these magnets have a wider operating temperature range, superior temperature coefficient and greater corrosion resistance. And start to outperform special high temperature neodymium magnets at 150°C.

SmCo magnets not only perform well at high temperatures, but also retain their magnetism at temperatures below absolute zero (-273°C), making them popular for cryogenic applications.

Since most grades of samarium cobalt contain little to no iron, they have excellent corrosion resistance.

 

Disadvantages

On the downside, due to the cost of producing cobalt, SmCo magnets can be more expensive compared to neodymium magnets (the cobalt market is price sensitive). Like other rare earth magnets, they are also very brittle, so they are best used in applications that do not require direct impact.

 

Application

Due to their properties, Samarium Cobalt magnets are most commonly used in applications requiring high operating temperatures such as generators, pump couplings, sensors, electric motors, marine applications as well as automotive, racing, aerospace, military and food and manufacturing industries.