Evaluation of Texture and Grain Size of Nanograined Copper Produced by the Accumulative Roll Bonding Process

Pure copper was intensely deformed by accumulative roll bonding (ARB) for up to eight cycles at ambient temperature. X-ray diffraction (XRD) was used to evaluate the grain size and texture during the ARB process. The Williamson–Hall method was used to calculate the grain size from the XRD patterns, which was about 30 nm after eight cycles of the ARB process. Texture analysis revealed cube texture in the initial copper. The intensity of cube texture decreased after one cycle of the ARB process. The texture of two-cycle ARB-processed sample was a transition texture, from cube to shear texture (rotated cube) that appeared after two cycles of ARB process in the subsurface regions. This shear texture developed due to shear deformation induced by the high level of friction between the rolls and the sheet. Moreover, shear texture was replaced by recrystallization texture (cube component) by annealing the ARB-processed samples. This result was caused by preferential growth of cube grains.