First laboratory X-ray diffraction contrast tomography for grain mapping of polycrystals

The first results of three-dimensional grain mapping using a laboratory tomograph equipped with a microfocus W target X-ray tube source, operated at 90 kV and 350 µA, are presented. Adapted algorithms exploit the polychromatic radiation spectrum and the projection magnification arising from the cone-beam geometry. The first map of grain shapes and crystallographic orientations from a titanium sample containing 42 grains is presented and its validity confirmed by a phase contrast reconstruction of the grain boundaries. Perspectives are given for the further development of the technique to accommodate samples with more grains or with greater intragranular orientation spread.