Ex-situ EBSD Study on the Abnormal Grain Growth in 6063 Aluminum Billet
Kanokwan Uttarasak, Wanchai Chongchitnan, Kenji Matsuda, Julathep Kajornchaiyakul and Chaiyasit Banjongprasert* Author for corresponding; e-mail address: chaiyasit.b@cmu.ac.th
Volume: Vol.47 No.2 (Special Issue I : March 2020)
Research Article
DOI:
Received: 20 September 2019, Revised: 20 November 2019, Accepted: 28 November 2019, Published: -
Citation: Uttarasak K., Chongchitnan W., Matsuda K., Kajornchaiyakul J. and Banjongprasert C., Ex-situ EBSD Study on the Abnormal Grain Growth in 6063 Aluminum Billet, Chiang Mai Journal of Science, 2020; 47(2): 242-258.
Abstract
The abnormal grain growth can occur in 6063 aluminum billet during homogenization. This behavior relates to the boundary migration and grain coalescence during homogenization. The Fe-containing intermetallics give strong retardation of boundary migration in 6063 aluminum alloy. The low (0.089wt.%Fe) and high (0.170wt.%Fe) containing 6063 aluminum billets were studied to gain an in-depth understanding of the individual of grain migration, grain coalescence, and abnormal grain growth in 6063 aluminum billet during homogenization. Ex-situ electron backscatter diffraction (Ex-situ EBSD) was extensively used to characterize those behaviors. Ex-situ EBSD results indicate that abnormal grain growth in 6063 aluminum billets is correlated to the migration of high angle boundary, which changes from a high angle to low angle grain boundary and to abnormal grain growth. The Fe-rich intermetallics prevent boundary movements and play an important role in recrystallization and abnormal grain growth. Keywords: Electron Backscatter Diffraction (EBSD), 6063 Aluminum Alloy, Abnormal Grain Growth, Recrystallization, Homogenization