Positron annihilation spectroscopy was used to study the influence of preparation route and processing on atomic free volumes in amorphous and nanocrystalline aluminium alloys. In melt-spun amorphous Al88Y7Fe5, structural free volumes smaller than a lattice vacancy were predominant, whereas in amorphous Al92Sm8 prepared by repeated cold rolling larger free volumes occur. In the early stages of nanocrystallization of Al88Y7Fe5, an indication of Y enrichment at interfacial free volumes in the growth front of the Al nanocrystallites was found.

Vacancy-Type Defects in Amorphous and Nanocrystalline Al Alloys - Variation with Preparation Route and Processing. W.Lechner, W.Puff, G.Wilde, R.Würschum: Scripta Materialia, 2010, 62[7], 439-42