Does SmCo permanent magnet need surface plating protection?
Samarium cobalt permanent magnet mainly includes the first generation of 1:5 type sintered samarium cobalt (SmCo5) permanent magnet and the second generation of 2:17 type sintered samarium cobalt (Sm2Co17) permanent magnet. It is the most representative type of cobalt based rare earth permanent magnet with high Curie point, good temperature stability, corrosion resistance and oxidation resistance.
Samarium, cobalt, copper, zinc and iron are the various elements that make up the samarium cobalt magnet.
SmCo permanent magnet is quite stable in dry air, cobalt does not react with water at room temperature, and it is also very stable in humid air. Cobalt has strong corrosion resistance, and the new phase formed by the two is also quite stable. It has strong oxidation resistance and corrosion resistance in dry, humid and high temperature environment. Therefore, the surface of sintered SmCo permanent magnet is not required at room temperature However, at high temperature (temperature > 400 ℃), samarium cobalt magnets are prone to dessamarium, resulting in the degradation of magnetic properties of magnets, so necessary surface protection is required.
In addition, in the practical application process, nickel plating will also be used to prevent bumps and epoxy plating will play an insulating role.