Residual stress and stored energy during recrystallisation in polycrystalline copper

Abstract

A general X-ray multireflection method was applied to determine the stress level in deformed and recrystallised polycrystalline copper samples. Different reflections hkl were simultaneously used in the fitting procedure. The anisotropic diffraction elastic constants were calculated using the self consistent model and crystallographic texture. A significant decrease of the first order residual stresses was observed during recovery and recrystallisation. Diffraction peak widths and intensities were also examined for a few characteristic texture components during the recrystallisation process. Independently, synchrotron radiation and electron backscatter diffraction techniques were used to determine the stored energy in the examined material. The main result is that residual stress components start to reduce already before the recrystallisation process. The stored energy is strongly orientation dependent. It has the lowest value in the cubic texture component, which is dominating one in recrystalisation texture.