Effects of intermediate annealing on the r-value of Al-Mg alloy sheets

Effects of intermediate annealing (IA) on the r-value and recrystallization texture in 5000 series aluminum alloy sheets containing magnesium of about 5wt.% were investigated. The r-values of recrystallization annealed sheets varied with the reduction in cold rolling after IA. The {145}[321] type recrystallization texture was formed in the low reduction of about 10%, while the {310}[132] type texture was observed in the high reduction over 40%. The restoration process was also changed with an increase in the reduction, from strain induced grain boundary migration type to nucleation and growth type. In the intermediate reduction region of about 30%, the observed texture was relatively random, probably due to a mixture of both the restoration processes. The processing window, to obtain good combination of the high r-value and less anisotropy, was discussed in terms of restoration in the final annealing and the resultant texture. (C) 1998 Published by Elsevier Science S.A. All rights reserved.