Ex-situ EBSD Study on the Abnormal Grain Growth in 6063 Aluminum Billet

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.