Grain growth process in Al-0.3mass%Mg alloy

Changes of the distributions of both grain orientation and grain boundary characters during grain growth in Al-0.3mass%Mg alloy have been investigated. Cold rolled specimens were isothermally annealed at 773K and microstructure of the specimen was observed with an optical microscope. Grain orientation was determined with X-ray diffraction and SEM-ECP methods, and grain boundaries were characterized with the Sigma value using SEM-ECP method. Frequency of Sigma 1 boundary increased with the average grain size at an early stage of grain growth, but it decreased in the latter stage. This complicated change in the frequency was well consistent with the change in the fraction of cube grains, and it was concluded to be a function of local distribution of cube grains and of Sigma 1 boundary in the initial structure.