Quantification of local dislocation density using 3D synchrotron monochromatic X-ray microdiffraction

A novel approach evolved from the classical Wilkens’ method has been developed to quantify the local dislocation density based on X-ray radial profiles obtained by 3D synchrotron monochromatic X-ray microdiffraction. A deformed Ni-based superalloy consisting of γ matrix and γ′ precipitates has been employed as model material. The quantitative results show that the local dislocation densities vary with the depths along the incident X-ray beam in both phases and are consistently higher in the γ matrix than in the γ′ precipitates. The results from X-ray microdiffraction are in general agreement with the transmission electron microscopic observations.