Definition and Characteristics of Samarium Cobalt Magnets, and Comparison with Neodymium-Iron-Boron Permanent Magnets

Samarium cobalt magnets, also known as samarium cobalt magnetic steel, samarium cobalt permanent magnets, and rare earth cobalt magnets, are high-performance, low-temperature coefficient permanent magnetic materials made from rare earth metals samarium and cobalt as the main raw materials, processed through a series of processes such as batching, melting, milling, pressing, sintering, etc. According to its composition, it is mainly divided into two series: sm2co17 and smco5.

Samarium cobalt magnets and neodymium magnets

Neodymium magnets have extremely high magnetic energy product (the maximum magnetic energy product can reach 54MGOE) and high energy density. Neodymium permanent magnets have been widely used in modern industry and electronic technology, achieving miniaturization and thinning of instruments, electroacoustic motors, magnetic selection, and magnetization equipment. Samarium cobalt magnets have high cost performance and good mechanical characteristics, but their Curie temperature is low, their temperature characteristics are poor, and they are easy to be pulverized and corroded. Samarium cobalt magnets must adjust their chemical composition, adopt surface treatment methods to improve their properties, and meet practical requirements.

Compared with neodymium magnets, samarium cobalt magnets have a slightly lower magnetic energy product. The maximum can only reach 33MGOE, but their Curie temperature is high and their temperature characteristics are good. Moreover, they are not easily corroded. Samarium cobalt magnets are widely used in aerospace, national defense, microwave devices, communications, medical equipment, motors, instruments, various magnetic transmission devices, sensors, magnetic processors, and magnetic lifting machines.

Characteristics of samarium cobalt magnets

Samarium cobalt magnets have excellent magnetic properties and good thermal stability, with a Curie temperature of around 800 degrees Celsius. Currently, some special grades of samarium cobalt permanent magnets can work at a maximum temperature of around 500 degrees Celsius. They have good chemical stability in the air, and are widely used in microwave communication technology, aerospace, national defense industry, transportation, high-speed driving, and other fields. However, samarium cobalt magnets contain expensive rare strategic metal elements such as cobalt and rare metal Sm, making them expensive and limiting their applications.

Unlike neodymium magnets, neodymium and other components are susceptible to oxidation and corrosion. Surface treatment processes are indispensable, and the life of the magnet largely depends on the effectiveness of the coating. Sm2co17 magnets in the samarium cobalt magnet series have low iron content, while SMCO5 magnets in the series basically do not contain iron. Therefore, samarium cobalt magnets are generally not easily oxidized and corroded. Except in harsh working environments, Sm2co17 magnets in the series need to be electroplated for aesthetics or to reduce edge breakage during assembly. Generally, samarium cobalt magnets do not require surface treatment.

Based on the above characteristics, the market prospects and important position of samarium cobalt magnets are crucial for modern industry, especially in some harsh application environments.