Semi in-situ observation of crystal rotation during cold rolling of commercially pure aluminum

Abstract

In this research, the validity of the deformation texture simulation based on the full-constraint (FC) Taylor model is assessed by a semi in-situ observation of crystal rotation during rolling. In order to study the deformation behavior of individual grains, successive rolling reductions (up to 24%) were applied to a split-sample of a commercially pure aluminum specimen. The electron backscattering diffraction (EBSD) technique was used to collect the crystallographic orientations and to investigate the microstructural evolution. The results indicate that as the deformation proceeds, the orientation spread inside the grains increases. Local variation of lattice rotation inside the grains results in the formation of a fragment boundary. As the deformation proceeds, the fragment boundary gradually moves through the original grain while it becomes narrower and carries a larger misorientation. However, up to the maximum rolling strain of 24%, the microstructural evolution did not give rise to massive generation of new high angle grain boundaries (HAGB). In general, the results of the texture predictions by the FC-Taylor model were found to be in reasonable agreement with the experimentally measured texture at low deformation. However, more plastic deformation resulted in a larger deviation. Study of individual grains rotation revealed large discrepancies in the simulated results of near cube orientations, which was attributed to the high symmetry of these orientations with respect to the deformation axis.