Crystallographic Aspects of Deformation and Recrystallization in ECAP-Processed AA3104 Aluminium Alloy

The objective of this study was to determine the effect of ECAP-processing on the texture and the microstructure development of the deformed and recrystallized states. The commercial purity AA3104 aluminum alloy was deformed via route A up to 7 passes and then annealed to obtain the state of partial recrystallization. The shear bands formation and the texture transformation in annealing were investigated with the use of high resolution transmission and scanning electron microscopes equipped with the facilitates for the local orientation measurements. It was found that the instability of the layered structure of the flat grains within some narrow areas led to the formation of the kink-type bands, which were precursors of the shear bands. The orientations of the new grains occurring in the recrystallized samples were not random, i.e. only specific groups of orientations were observed. In most of the observed cases, the growth of the recrystallized grains led to nearly homogeneous equiaxed grains of a similar size.