Permanent SmCo Magnets

Are you looking for a powerful and stable permanent magnet for your industrial or scientific applications? Look no further than the samarium–cobalt (SmCo) magnet!

SmCo magnets, a type of rare earth magnet, were developed in the early 1960s by Dr. Karl Strnat and Dr. Alden Rey at Wright-Patterson AFB and the University of Dayton. These magnets are made of an alloy of samarium and cobalt and are considered by many to be the best permanent magnet material commercially available.

With remanence similar to neodymium magnets, SmCo magnets have higher temperature ratings and superior temperature stability, making them arguably the best permanent magnet material commercially available. There are two types of SmCo magnets to choose from: SmCo 1:5 and SmCo 2:17.

The samarium–cobalt 1:5 magnet alloys (generally written as SmCo5 or SmCo 1:5) have one atom of rare earth samarium per five atoms of cobalt. By weight, this magnet alloy typically contains 36% samarium with the balance being cobalt. Sometimes Prasedymium is alloyed to increase the remanence.

The energy products of these samarium–cobalt alloys range from 16 MGOe to 25 MGOe, which is approximately 128 – 200 kJ/m3. Compared to SmCo 2:17 magnets, the 1:5 magnets are relatively easy to magnetize and saturation magnetization can be achieved with a moderate magnetizing field. Therefore, 1:5 magnets are easier to calibrate to a specific magnetic field.

On the other hand, Sm2Co17 magnets (also known as SmCo Series 2:17) are age-hardened with a composition of two atoms of rare-earth samarium per 13–17 atoms of transition metals (TM). The TM content is rich in cobalt but also contains other metals such as iron and copper. Other elements like Zirconium and Hafnium may be added in small quantities to achieve better heat treatment response.

The maximum energy products of these alloys range from 20 to 32 MGOe, which is about 160-260 kJ/m3. These alloys have the best reversible temperature coefficient of remanence of all rare-earth alloys, typically being -0.03%/°C.

The coercivity mechanism in Sm2Co17 magnets is based on domain wall pinning, unlike in SmCo 1:5 and NdFeB magnets where it’s nucleation. The purpose of alloying and heat treatment is to create a microstructure inside the magnets that impedes domain wall motion and thereby resists the magnetization reversal process.

SmCo magnets can withstand temperatures up to 350°C without losing their magnetic properties and are the ultimate solution for high-temperature applications that require strong and stable magnetic properties. Their superior temperature stability, combined with their high-energy products and unique composition, make them an excellent choice for a variety of industries, including aerospace, defense, and energy.

If you need a strong, stable, and reliable permanent magnet for your industrial or scientific applications, consider the samarium–cobalt (SmCo) magnet. With options like SmCo 1:5 and SmCo 2:17 to choose from, you can select the best fit for your specific needs.

SmCo Magnets Making Process

Samarium Cobalt (SmCo) magnets are produced using powder metallurgy techniques. Firstly, the raw materials are melted in a furnace and cast into thin sheets or ingots. The material is then crushed and pulverized using either ball milling or jet milling.

Next, the powder is oriented using an external magnetic field and pressed into blocks or near-net shapes. The final properties and density of the magnet are achieved through sintering and heat treatments. Finally, the blocks are cut into their desired shape and magnetized.

Through this carefully controlled process, we can produce two types of SmCo magnets with different magnetic properties. Both types of SmCo magnets are known for their superior magnetic strength and stability, making them ideal for high-performance applications where reliability is essential.

By utilizing these advanced manufacturing techniques, SmCo magnets can deliver unmatched performance and meet the most demanding industrial requirements.

Magnetic Properties of SmCo Magnets

Physical Properties of SmCo Magnets

Applications of SmCo Magnets

SmCo magnets are used in a variety of applications, including:

1. Motors and generators: SmCo magnets are commonly used in the manufacturing of electric motors and generators, as they offer high stability and reliability.
2. Aerospace and defense: SmCo magnets are used in aerospace and defense applications due to their high resistance to demagnetization and their ability to operate in extreme temperature environments.
3. Medical equipment: SmCo magnets are used in medical imaging equipment, such as MRI machines, due to their high magnetic field strength and stability.
4. Sensors: SmCo magnets are used in sensors, such as magnetoresistive sensors, due to their high magnetic field strength and stability.

Advantages of SmCo Magnets

1. High magnetic energy density: SmCo magnets have a high magnetic energy density, which means that they can produce a strong magnetic field in a small size.
2. High resistance to demagnetization: SmCo magnets have a high resistance to demagnetization, making them ideal for applications where high stability and reliability are required.
3. High maximum operating temperature: SmCo magnets have a high maximum operating temperature, making them suitable for high-temperature applications.
4. Low thermal expansion coefficient: SmCo magnets have a low thermal expansion coefficient, which means that their size remains stable even when exposed to temperature changes.

In conclusion, SmCo magnets are a type of rare earth magnet with exceptional magnetic properties. They have a high magnetic energy density, high resistance to demagnetization, high maximum operating temperature, and low thermal expansion coefficient. These properties make SmCo magnets ideal for applications in the motors and generators, aerospace and defense, medical equipment, and sensors industries.