Modelling the initial stage of grain subdivision with the help of a coupled substructure and texture evolution algorithm

The substructure development in f.c.c. monocrystals and polycrystal grains under cold rolling is modelled with the help of evolution equations for the densities of redundant cell wall and non-redundant fragment boundary dislo cations as well as of mobile and immobile disclinations in six cell wall an d fragment boundary families. The slip rates for the I? f.c.c. slip systems are calculated by a full constraints Taylor algorithm. The critical resolv ed shear stresses are derived from the dislocation and disclination densiti es. Substructure and crystal orientation are updated alternately in each in tegration step. The model is able to predict cell wall and fragment boundar y spacings as well as misorientations in reasonable agreement with experime ntal data obtained in TEM studies on aluminium. The subset of preferably sp litting grains in a polycrystal is found in reasonable agreement with OIM r esults. (C) 2001 All Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.