High-pressure torsion was applied to the structural refinement of an age-hardenable Al–Cu–Mg–Mn alloy (AW 2017). This deformation gives rise to a fragmentation and dissolution of aging-induced precipitates and to a grain refinement down to sizes of 100nm. Positron annihilation spectroscopy, in particular the chemical sensitive method of two-dimensional Doppler broadening spectroscopy, was used for a detailed analysis of the nature of vacancy-type defects induced by deformation and vacancy–solute interaction. The correlation between microstructure and atomic defects with thermal annealing was discussed.

Microstructure and Vacancy-Type Defects in High-Pressure Torsion Deformed Al–Cu–Mg–Mn Alloy. W.Lechner, W.Puff, B.Mingler, M.J.Zehetbauer, R.Würschum: Scripta Materialia, 2009, 61[4], 383-6