Structure and electromagnetic characteristics of flaky FeSiAl powders made by melt-quenching

Soft magnetic metallic material has been widely used for electromagnetic wave absorption application. Recent work [J. Appl. Phys. 93 (2003) 6659] proved that flaky morphology with large aspect ratio could further improve the absorption ability of these powders. Therefore, FeSiAl (8.6 wt%Si-6 wt%Al-bal Fe) flaky powders are prepared from melt-quenched ribbons by annealing and milling. It is found that D03 superlattice ordered structure increases with increasing annealing temperature in the ribbons. During the milling process, the change of the pair number of bond covalent electrons in (1 1 1) plane results in the change of the magnetization of as-milled powders. Annealed at 873 K, the maximal value of μ' and μ'' of powders milled for 70 h are 5.5 and 4.5 respectively, with large saturation magnetization (90.43 A m2 kg-1), indicating good absorption performance.