Abnormal Grain Growth on the Surface of Cold-Rolled AA1235 Aluminum Plate during the Annealing Process

AA1235 aluminum alloys were twin roll cast into a 7.0 mm-thick billet and further rolled into a plate with 70% reduction, followed by annealing at 500 C for 8 h. Abnormal grains were found to be formed on the plate bottom surface. SEM, EBSD, and micro X-ray diffraction were used to analyze the mechanism underlying the abnormal growth of these grains. Results showed that the {100} texture was formed in the surrounding normal grains adjacent to the abnormal grain. The orientation angle between the abnormal grain and its adjacent normal grains was 45°. The {100} texture formed during rolling and annealing accelerated abnormal grain growth. The partially dissolved Fe precipitates were heterogeneously distributed in the plate bottom heterogeneously, which also mainly explained abnormal grain growth.