Long-term effects of electrochemical corrosion on magnetic properties of sintered NdFeB magnets

摘要

Immersion tests and magnetic property measurements were used to study the long-term effects of electrochemical corrosion on the magnetic properties of sintered NdFeB magnets. The results revealed that, during electrochemical corrosion, uneven distribution of the Nd-rich phase caused local lattice expansion in the magnets, in which the priority nucleation of reversal domains occurred. By analyzing the measurement results, about 90% of the remanence (B_r) loss was ascribed to the matrix phase loss, while the remaining 10% was attributed to the deterioration of the surface structure of the magnets during electrochemical corrosion.