Development of nanocrystalline Fe–Co alloys using mechanical alloying

Abstract

Nanostructured alloys have considerable potential as soft magnetic materials. In these materials a small magnetic anisotropy is desired, which necessitates the choice of cubic crystalline phases of Fe, Co, Ni, etc. In the present work, Fe–50 at.-%Co alloys were prepared using mechanical alloying (MA) in a planetary ball mill under a controlled environment. The influence of milling parameters on the crystallinity and crystal size in the alloys was studied. The particle size and morphology were also investigated using SEM. In addition, a thermal treatment was employed for partial sintering of some of the MA powders. The crystal size in both MA powders and compacted samples was measured using X-ray diffraction. It was shown that the crystal size could be reduced to less than 15 nm in these alloys. The nanocrystalline material obtained was also evaluated for magnetic behaviour.