Thermal stability of nanostructured Al93Fe3Cr2Ti2 alloys prepared via mechanical alloying

Thermal stability of nanostructured Al93Fe3Ti2Cr2 alloys prepared via mechanical alloying (MA) starting from elemental powders was investigated using a variety of analytical techniques including modulated differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, transmission electron microscopy coupled with energy dispersive spectrometry and microdiffraction. The results showed that the MA-processed Al93Fe3Ti2Cr2 alloy in the as-milled condition was composed of an Al-based supersaturated solid solution with high internal strains. Release of internal strains, intermetallic precipitation and grain growth occurred upon heating of the MA-processed Al alloy. Nevertheless, grain growth in the MA-processed At alloy was very limited and fcc-Al grains with sizes in the range of 20 nm were still present in the alloys after exposure to 450 degreesC (0.77 T-m). (C) 2003 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.