On phase transformations in mechanically alloyed and subsequently annealed Al70Cu20Fe10

In the present work, phase transformations during mechanical alloying (MA) and post-MA annealing of Al70Cu20Fe10 have been investigated using X-ray diffraction (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). No icosahedral quasicrystalline phase (i-phase) is observed during the milling process of Al70Cu20Fe10. A totally disordered β-Al(Cu,Fe) phase firstly forms in the as-milled powders after 40 h of MA and thus transforms into the stable β-phase with a B2 structure with increasing milling time up to 70 h. The i-phase appears in the as-annealed products and its amount increases with increasing milling time. In addition, the ω-Al7Cu2Fe phase only forms after heat treatment of the milled Al70Cu20Fe10 powders. Furthermore, the formation of both the i-phase and ω-phase depends upon the milling time and annealing temperature.