Recrystallization texture evolution of cold-rolled Cu foils governed by microstructural and sample geometrical factors during heating

Abstract

With the increased use of 2D materials for instrument minimization, research on recrystallization texture of cold-deformed metal foils during annealing becomes attractive, as the recrystallization process is also subjected to external constraints (biaxial thermal strain and surface energy) in addition to the microstructural factors. In this work, the orientation evolution of cold-rolled Cu foils (10 μm thick) during heating was thoroughly investigated macroscopically by neutron and synchrotron radiation diffraction and microscopically by SEM-EBSD, combined with crystallographic analysis. The results showed that the foils underwent a transition from the cold-rolling texture to a recrystallization texture dominated by two rotated orientations, i.e., RD-rotated Cube and φ2-rotated Copper. The transition was screened by both intrinsic microstructural and extrinsic geometrical factors. The orientations of the nuclei were mainly inherited from the deformation orientations. Those with low Taylor factors (Cube, Goss and Brass) demonstrated size preference. The post-nucleation growth was affected by the biaxial thermal elastic constraint and surface energy. Due to their opposite effects, the orientations having moderate biaxial moduli and surface energy density (S, Copper, Brass and recrystallization components) survived, resulting in a mixed texture at the completion of recrystallization. The coherent Σ3 boundaries between the new components stabilized their growth through consuming the other crystals separated by random high-angle boundaries. The present results provide quantitative information on recrystallization texture and contribute to deepening the understanding of the recrystallization behavior of cold-worked metals.