Computational or Experimental? Interpreting X-ray Absorption and Diffraction Contrast for Massive Non-Destructive 3D Grain Mapping of Metals in Laboratory CT

Laboratory 3D X-ray microscopy (XRM) has previously been limited to imaging via material density differences within the sample. As such, single-phase polycrystalline materials (e.g. alloys) do not exhibit any absorption contrast to reveal the underlying grain microstructure. For microstructural crystallography, researchers have turned to time-consuming 3D electron backscatter diffraction in the scanning electron microscope in metallurgy, ceramics, semiconductors, pharmaceuticals, geology etc.

Now, laboratory-based diffraction contrast tomography (DCT) can extract crystallographic information from single-phase polycrystalline samples, non-destructively and in three dimensions. DCT scans collect x-ray diffraction patterns which are deconvoluted for crystallographic reconstruction. Information on grain morphology, orientation, size and centroid position is available from the reconstructed 3D grain map, for studies of grain growth, tensile testing and aniostropy, delivering explicit grain structures for modeling.

We show how LabDCT provides a routine solution for experimentally acquiring explicit 3D grain structures in various materials, enabling direct coupling of experimental results and simulations.