What Is Samarium Cobalt Magnet?

What is samarium cobalt magnet?

Samarium cobalt magnet, also known as samarium cobalt permanent magnet, is a kind of strong permanent magnet made of samarium and cobalt. Like NdFeB, it also belongs to rare earth magnets. At present, it mainly consists of SmCo5 and Sm2Co17.

Although the magnetic force of SmCo is not so strong as that of NdFeB, SmCo has two obvious advantages: higher temperature range and better corrosion resistance. Therefore, they provide the best value when comparing performance and size in high temperature environments or applications.

 

History of SmCo magnets:

Samarium cobalt magnets introduced in 1970s are the first batch of commercial rare earth magnets. Their launch was revolutionary and tripled the maximum energy product of any other magnet at the time. Before the introduction of SmCo magnets, the standard of magnetism was alnico alloy magnets. Until rising production costs led engineers to look for cheaper alternatives, neodymium magnets were developed and are now the strongest magnets in the world.

 

Advantages of SmCo permanent magnets:

SmCo magnets are not as powerful as super neodymium magnets, but they have some obvious advantages. SmCo magnets have a wider operating temperature range, superior temperature coefficient and greater corrosion resistance. It is better than the special high temperature neodymium magnet at 150 ℃.

SmCo magnets not only perform well at high temperatures, but also maintain their magnetism even at temperatures below absolute zero (- 273 ℃), so they are very popular in low temperature applications.

Because most grades of samarium cobalt contain little iron, they have excellent corrosion resistance.

 

Disadvantages of SmCo magnets:

On the other hand, due to the cost of producing cobalt, samarium cobalt magnets may be more expensive than neodymium magnets (cobalt market price sensitive). Like other rare earth magnets, they are also very brittle, so they are most suitable for applications that do not require direct impact.

 

Applications of SmCo magnets:

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