Direct determination of elastic strains and dislocation densities in individual subgrains in deformation structures

A novel synchrotron-based technique "high angular resolution 3DXRD" is presented in detail, and applied to the characterization of oxygen-free, high-conductivity copper at a tensile deformation of 2%. The position and shape in reciprocal space of 14 peaks originating from deeply embedded individual subgrains is reported. From this dataset the density of redundant dislocations in the individual subgrains is inferred to be below 12 × 10¹² m^-2 on average. It is found that the subgrains on average experience a reduction in strain of 0.9 × 10^-4 with respect to the mean elastic strain of the full grain, a rather wide distribution of the strain difference between the subgrains (twice the standard deviation is 2.9 × 10^-4), and a narrow internal strain distribution (upper limit is 2.4 × 10^-4 full width at half maximum).