The deformed microstructure and recrystallization behavior of copper samples processed
using equal channel angular extrusion (ECAE) have been investigated. The heavily deformed
microstructure was found to be non-uniform through the sample thickness and to vary in a manner
consistent with the non-uniform distribution of strain imposed by processing. The through-thickness
heterogeneity of the deformed microstructure resulted in a different extent of recrystallization in
different layers during annealing. Recrystallized grains were also observed in samples that were not
annealed, but stored at room temperature, which indicates that the deformed microstructure of
ECAE-processed pure copper is unstable even at room temperature. In each sample,
recrystallization was found to initiate in regions containing predominantly large misorientations.