Al-Fe Solid solutions in alloys obtained by melt spinning

The extension of solid solutions is one of the more claimed effects of solidification under high cooling rates. The possibility to increase, by such technology, the extremely small amount (0,006 at% at 500 C) of iron in aluminum was extensively studied and recently received further attention, owing to the interesting technological properties of Al-Fe alloys. However the rapid quenching from the liquid not only affects the amount of iron retained in solid solution, but also the possible formation of other intermetallic phases, and, more generally, the location of iron atoms retained in the metastable solid solution of aluminum. Different situations of iron atoms have been investigated using XRD, TEM and Moessbauer spectroscopy (MS), but from the interpretation of the results some problems to obtain unambiguous conclusions arise. In any case it seems interesting to clarify the actual extension of solubility of iron in aluminum, in rather concentrated alloys, in which the formation of metastable intermetallic compounds cannot be suppressed. The paper reports MS analysis of Al-Fe (0,1--4 at%) alloys, rapidly solidified by melt spinning.