Nanocrystalline FeAl intermetallics obtained in mechanically alloyed Fe50Al40Ni10 powder

B2-Fe47Al53 intermetallics has been produced by mechanical alloying in a planetary ball mill, using elemental Fe, Al and Ni powder mixture. The microstructural and magnetic properties of the mechanically alloyed Fe50Al40Ni10 powdered samples were investigated by X-ray diffraction and 57Fe Mössbauer spectrometry at 300 and 77 K. As resulted from the X-ray diffraction studies, the ordered B2 structure was formed in the Fe50Al40Ni10 powder, together with the bcc αi-Fe(Al, Ni) (i = 1, 2) solid solutions. Further milling led to a partial disordering of B2-Fe47Al53; it has undergone an order–disorder transition which is characterized by an expansion of the volume Δa0 (lattice disorder) and a magnetic transition from the paramagnetic to ferromagnetic state which is characterized by strong ferromagnetic interactions in the alloy. The nanocrystalline bcc αi-Fe(Al, Ni) solid solution was ferromagnetic with a mean crystallite size of 6 nm.