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

摘要

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 percent. 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 sub-grains is inferred to be below 12 X 10~(12) m~(-2) on average. It is found that the subgrains on average experience a reduction in strain of 0.9 X 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 X 10~(-4)), and a narrow internal strain distribution (upper limit is 2.4 X 10~(-4) full width at half maximum).