The magnetic properties and microstructure of phosphated amorphous FeSiCr/silane soft magnetic composite

摘要

Herein, amorphous FeSiCr phosphating powders were prepared using two phosphating methods and were further formed into soft magnetic composites (SMCs). The effects of phosphating treatment on the morphology and composition of phosphate layers of amorphous FeSiCr particles and mechanisms of the phosphating process were investigated via scanning electron microscopy, X-ray diffraction (XRD), Fourier transform infrared spectra, and X-ray photoelectron spectroscopy. The magnetic properties of amorphous FeSiCr phosphating powders were determined via the Quantum Design vibrating sample magnetometer. The effects of heat and phosphating treatments on AC magnetic properties of SMCs were investigated using a B-H curve analyzer. Results showed that both phosphating treatments significantly increase the resistivity of amorphous FeSiCr and do not deteriorate its magnetic properties. However, owing to the thick phosphating layer of amorphous FeSiCr phosphate on the zinc phosphate solution, its compressibility deteriorated. The magnetic permeability of the SMC was very stable in the frequency range of 10-500 kHz. Following heat treatment at 500 degrees C in an argon atmosphere, the magnetic permeability of the SMC significantly increased, whereas the magnetic loss significantly reduced.