Effect of Cooling Rate after Hot Rolling on the Microstructure and Texture Evolution of an AA1050 aluminum Processed by Cold Rolling and Annealing

• Main Authors: Chia-hao Chang, 張家豪
• Other Authors: Pei-ling Sun
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/96691781309863759777

碩士 === 國立中山大學 === 材料與光電科學學系研究所 === 104 === In this study, a commercially pure aluminum AA1050 was hot rolled and cooled to room temperature with different cooling speeds: furnace cooled (FC) and water quenched (WQ). These two materials were then cold rolled (CR) 90% in reduction. The microstructures and textures were analyzed on these CR specimens to study the cooling rate effect after hot rolling. After cold rolling, the textures of the FC and WQ sample are different. It has been proved that the rolling textures of the FCC metals with high stacking fault energy is mainly β-fiber. The intensity of β-fiber in the WQ specimen is higher than that in FC specimen. After annealing treatment, the recrystallization texture, which is Cube orientation can be measured in the FC sample. However, no Cube orientation was detected in WQ sample up to annealing temperature of 300°C. Electron backscatter diffraction (EBSD) experiments were performed on the same areas for the CR and annealed specimens to allow the direct comparisons of the CR microstructures and annealed microstructures. The experimental results indicate that recrystallization appears at the areas with high angle grain boundaries in the CR states. With the increasing of annealing time and temperature, it is found that the Cube oriented grains which located nearby S oriented grains in the CR FC sample grow after annealing treatment. Therefore, the growth of Cube oriented grains is proved to be associated with their surrounding microstructures. For the WQ sample, grains were found to coarsen after annealing treatment and the recrystallization Cube oriented grains were not detected.