The effect of thermomechanical processing upon the hardness and defect structure of Al-2.5Cu-1.5wt%Mg alloy was examined by using hardness measurements and transmission electron microscopy. The rapid age-hardening reaction, which contributed some 70% of the total hardening response of the alloy, was found to be higher than that which arose from up to 3% rolling. The hardening effect which arose from an aging/deformation/aging processing sequence was shown to be slightly greater than that which arose when deformation immediately followed quenching. The defect structures which were produced by these 2 processing routes was distinctly different, in that dislocation loops and helices predominated in samples which were aged before deformation. The dislocation tangles which were introduced, when deformation was the initial step after quenching, persisted throughout subsequent aging and restricted the growth of loops and helices.

Hardening and Defect Structures in Thermomechanically Processed Al-2.5Cu-1.5wt%Mg Alloy. K.Raviprasad, C.R.Hutchinson, S.P.Ringer: Materials Science Forum, 2000, 331-337, 1077-82