Time-resolved SR study on evolution of dislocation structures in polycrystalline copper under uniaxial loading

Abstract

The purpose of this study is to investigate the evolution of dislocation structure in polycrystalline copper under uniaxial loading by an in situ X-ray diffraction experiment using synchrotron radiation. The dislocation structures are characterized in terms of dislocation density and the spatial fluctuation of their distribution from the Fourier analysis of broadened X-ray line profiles. Some conclusions from this work are as follows: (a) the dynamic evolution of dislocation density and its spatial fluctuation during deformation exhibits some fluctuation, not a merely monotonic behavior, as has been generally accepted for the case of static (unloaded) dislocation structure in plastically deformed metals; (b) dynamic recovery is ascribed mainly to a rearrangement of dislocations; (c) the variation of dislocation density in the cell walls and cell interiors asserts a nearly periodic rearrangement and/or annihilation of dislocations.