Sintered NdFeB permanent magnet materials are produced by powder metallurgy process. It is a powder material with very strong chemical activity. There are tiny pores and cavities inside, which are easily corroded and oxidized in the air. The experimental results show
that a 1cm³ sintered NdFeB permanent magnet will be completely oxidized and corroded when placed in air at 150°C for 51 days. After the magnetic material is corroded or the components are damaged, the magnetism will attenuate or even lose as time goes by, which will affect the performance and life of the whole machine, so strict anti-corrosion treatment must be carried out before use.
