Abstract
The coherent edge interface structures of the relatively thin {111}Al Ω plates have been analyzed in a peak-aged Al-Cu-Mg-Ag alloy by atomic-resolution scanning transmission electron microscopy (STEM). Analysis of STEM images showed that these edge interfaces can deviate from their orthogonal orientations to the broad plate surfaces. The edge interface tilts correlate with orientations of the shear components appearing along the broad plate surfaces and changing with the plate thicknesses. Cu atoms tend to occupy specific atomic sites in the Al matrix region close to the edge interfaces.