The evolution of microstructure and magnetic properties of Fe-Si-Cr powders on ball-milling process

Flake-shaped particles were fabricated from crushing ingots with ball milling method. Scanning electron microscope (SEM), X-ray diffraction (XRD), vibrating samples magnetometer (VSM) and Mossbauer spectroscopy measurements were carried out to characterize the milled powders. The XRD results show that the DO3 ordered phase coexists with alpha-Fe(Si,Cr) matrix phase. Generally, grain size decreases with milling time, as internal strain increases. The fitting result of the Mossbauer spectra of the as-prepared powders reveals that the DO3 phase always exists, but the percentage of DO3 phase drops from 52% in the starting powder to 25% after 80 h milling. A planar anisotropy of the flake-shaped powders is also demonstrated by the Mossbauer spectra, and found to increase with milling time. The saturation magnetization M-s has a maximum value of 109 emu/g after milling of 8 h, and then remains at a steady value around 104 emu/g. The maximum complex permeability is obtained by 32 h milling. (C) 2013 Elsevier B. V. All rights reserved.