In-situ annealing and computation study of cube texture development in a commercial aluminum alloyThe aim of this study was to identify the physical processes of nucleation and growth of cube grains by means of in-situ annealing experiments. The calculated nucleation site density at cube bands was found not to be sufficient for a correct computational prediction of the cube recrystallization texture. Growth competition at an early stage of recrystallization has to be taken into account for a better agreement between model and experiment, which necessitates a sufficiently refined grid resolution in discrete computer models of recrystallization. Accounting for these dependencies yields an excellent prediction of both the cube component in the recrystallization texture and the grain size distribution. The contribution of cube nucleation apart from cube bands to the cube recrystallization texture was found to be negligible.

In the present study, the substructure within grains of different orientations was investigated by means of EBSD technique. A 70% cold rolled commercial AA8079L alloy was annealed at two temperatures, 280°C and 320°C, for short times from 2 to 60 seconds. The subgrain size within the deformed grains of different orientations was measured. The results revealed no pronounced difference in subgrain size right after cold deformation. During further annealing at both investigated temperatures, Cube grains showed the highest recovery rate. It is concluded that the Cube oriented nuclei require an incubation time which is, obviously, much smaller than for grains of other orientations.

In the present study, a modified cellular automaton CORe (Cellular Operator for Recrystallization) was used to predict the recrystallization (RX) texture and microstructure of 70% cold rolled commercial AA8079L alloy at 300°C. The nucleation of the Cube orientation is of considerable scientific interest since the Cube texture component influences significantly the anisotropy of material properties. Experimental data collected during this investigation were used for subsequent modeling. By studying the annealed material by EBSD, an average nucleation rate at Cube bands was established and used in the model. The simulated microstructure reveals, in general, good agreement with experiment. The texture prediction shows the right tendency, but the modeled intensity of the Cube texture is about 2 times smaller than in experiment.

In the current study the nucleation of Cube grains during recrystallization in a commercial Al-Fe-Si alloy was investigated by in-situ and ex-situ annealing experiments at different temperatures. Both methods confirm that the Cube grains can be nucleated during RX both at large deformed Cube bands and other locations. During annealing only about one third of the Cube nuclei from these other locations developed into Cube oriented recrystallized grains owing to an unfavorable growth environment. Such nuclei needed also a longer incubation time due to their small size compared to nuclei formed at large Cube bands which can form nuclei very fast owing to the well-developed substructure and transition zones promoting nucleation. The growth rate of all Cube nuclei was found to be strongly influenced by their environment. This effect became more pronounced with decreasing annealing temperature due to an increasing amount of recovery.

In the present study, nucleation at Cube bands during annealing of a cold rolled commercial aluminium alloy AA8079 was investigated. The main goal of this work was to provide experimental data for subsequent modelling. By studying the deformed material the geometrical parameters of Cube bands were determined. The Cube band spacing in the deformed state was measured experimentally and accordingly calculated with a simple geometric model, taking the initial Cube fraction in the pre-deformed state and the deformation degree into account. The nucleation frequency during subsequent annealing of the cold deformed material was estimated from the geometry and size of deformed Cube bands prior to deformation. From investigations of the orientation relationship between the Cube oriented nuclei and the adjacent deformed matrix with S orientation, the fraction of 40°<111> grain boundaries having optimum growth conditions, was established.