Through-Thickness Characterization of Microstructure and Texture in High Purity Aluminum Processed to High Strain by Accumulative Roll-Bonding
Naoya Kamikawa, Nobuhiro Tsuji, Xiaoxu Huang, Niels Hansen
The deformation microstructure and texture have been characterized by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) through the thickness of high purity (99.99% purity) aluminum sheets processed by accumulative roll-bonding (ARB) up to a total strain of 4.8. This processing route creates a complex strain path, resulting in a characteristic texture changes through the thickness of the sample, very different from that obtained by conventional rolling, and also in a randomization of the overall deformation texture. The microstructure is composed of an equiaxed structure with a high concentration of high-angle boundaries and a small fraction of a lamellar structure with a high concentration of low-angle boundaries. The observations showed a coupling between the local texture and microstructure; the equiaxed regions are composed of deformation texture components and random texture components while the lamellar regions are composed of the deformation texture components, i.e. rolling or shear texture components.