Orientation Evolution and Nucleation Mechanism of UFG-Copper Prepared by SD-AARB with Heat Treatment

Abstract

Ultra-Fine-Grained (UFG) copper strip was prepared by severe deformation method of asymmetrical accumulative rolling bond (SD-AARB) with heat treatment, in which the reduction rate of 1.08 was employed with 50% rolling reduction by six passes(4.8 true strains). The heat treatment was conducted at annealing temperature of 220°C for 5~55 minutes. EBSD and X-ray diffraction were employed to follow the features of texture and orientations. The texture formulation mechanism of deformed copper recrystallized nucleation was studied. The results show that the deformation textures developed in the copper strip by SD-AARB are very similar to those by common the cold rolling process, which is {112}<111>. After the annealing treatment, the strength of the main texture components in the oxygen-free pure copper is decreased along with the extension of recrystallization annealing time, which is C,R,S and B/G texture components. For high energy release rate, grains of all kinds of orientations have the chance of nucleation and growing up, which is different to traditional recrystallized cube texture.