Evolution of magnetic loss with annealing temperature in FeSiAl/carbonl iron soft magnetic composite

摘要

The evolution of magnetic loss of FeSiAl/carbonyl iron powder cores annealed at diferent temperatures was investigated. The experimental results reveal that the magnetic permeability of FeSiAl/carbonyl iron core increases as the annealing temperature increases, but it almost remains constant when annealing temperature higher than 650°C. The magnetic loss of the core frst decreases with the increase of the annealing temperature, reaches a minimum at about 640°C, and then starts to increase with further annealing temperature increasing. It is found in loss separation that both hysteresis loss and excess loss decrease with the increase of annealing temperature before 640°C, which can be attributed to the reduction of efective anisotropy caused by stress relief. However, the eddy current loss increases with annealing temperature increasing when it is higher than 650°C, which may be the result of the degradation of the surface insulation layer caused by the high temperature annealing.