Factory supply SmCo Samarium Cobalt Block Magnets

Samarium cobalt (SmCo) block magnets are composed of samarium, cobalt and iron. Samarium cobalt magnets are valued for their superior strength relative to their size. Even at extremely low or high temperatures these magnets resist demagnetization and corrosion.

SmCo is argueably the best permanent magnet material commercially available, with remanence similar to neodymium magnets, but with higher temperature ratings and with superior temperature stability. There are two types of SmCo magnets, SmCo 1:5 and SmCo 2:17.

Manufacturing process

Both the types of SmCo magnets are manufacture by powder metallurgy. The raw materials are melted in a furnace and cast into thin sheet or ingot. The material is crushed and then pulverized by ball milling or by jet milling. The powder is then oriented with external magnetic field and pressed into blocks or near net shape. Final properties and density are achivied in following sintering and heat treatments. The blocks are then cut to shape and magnetized.

SmCo 1:5

As the nomination indicates, 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 will typically contain 36% samarium with the balance cobalt. Sometimes Prasedymium is alloyed to increase the remanence. The energy products of these samarium-cobalt alloys range from 16 MGOe to 25 MGOe, that is, approx. 128 - 200 kJ/m3. Contrary 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 than the SmCo 2:17 magnets.

SmCo 2:17

These alloys (written as Sm2Co17, or 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 contains also other metals such as iron and copper. Other elements like Zirkonium and Hafnium etc. 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, what 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.

In Sm2Co17 magnets, the coercivity mechanism is based on domain wall pinning (in contrary to SmCo 1:5 and NdFeB where it's nucleation). The purpose of alloying and heat treatment is to create a microstructure inside the magnets which impede the domain wall motion and thereby resist the magnetization reversal process.

Physical performance sheet of sintered SmCo

Applications for Samarium Cobalt

Samarium Cobalt block Magnets are used in applications that include motor, medical, research, sensor, holding, consumer electronics, consumer products, and automotive. These Rectangle Magnets can withstand high temperature and other demagnetizing forces.

FAQ: 

Q1. What are the characteristics of SmCo Block Magnets?

A1. SmCo Block Magnets have high magnetic strength, excellent temperature stability, and high resistance to demagnetization. They are also brittle and relatively expensive compared to other types of magnets.

Q2. What are the applications of SmCo Block Magnets?

A2. SmCo Block Magnets are used in various industrial applications, including sensors, pumps, and motors. They are also used in scientific, medical and automotive industries.

Q3. How are SmCo Block Magnets made?

A3. SmCo Block Magnets are manufactured through a process called powder metallurgy, which involves the mixing of raw materials, pressing them into the desired shape, and then sintering the magnet in a furnace.

Q4. What are the advantages of SmCo Block Magnets?

A4. SmCo Block Magnets have high magnetic strength, excellent temperature stability, and high resistance to demagnetization. They are also resistant to corrosion and do not require coatings.

Q5. Can SmCo Block Magnets be customized?

A5. Yes, SmCo Block Magnets can be made in various sizes and shapes depending on the specific application.