X-ray orientation microscopy using topo-tomography and multi-mode diffraction contrast tomography

Abstract

Polycrystal orientation mapping techniques based on full-field acquisition schemes like X-ray Diffraction Contrast Tomography and certain other variants of 3D X-ray Diffraction or near-field High Energy Diffraction Microscopy enable time efficient mapping of 3D grain microstructures. The spatial resolution obtained with this class of monochromatic beam X-ray diffraction imaging approaches remains typically below the ultimate spatial resolution achievable with X-ray imaging detectors. Introducing a generalised reconstruction framework enabling the combination of acquisitions with different detector pixel size and sample tilt settings provide a pathway towards 3D orientation mapping with a spatial resolution approaching the one of state of the art X-ray imaging detector systems.

<i>In-situ</i> Tensile Tester for Scanning Three-Dimensional X-ray Diffraction Microscopy

“…In the past two decades, non-destructive 3D OM methods without serial sectioning have been proposed using third-generation synchrotron-based x-ray diffraction and imaging techniques such as diffraction contrast tomography (DCT), [3][4][5][6][7] 3D x-ray diffraction (3DXRD) microscopy, [8][9][10][11][12][13][14][15][16][17][18][19][20][21] high-energy diffraction microscopy (HEDM), [22][23][24][25][26][27][28][29][30][31][32][33][34] scanning 3DXRD, [35][36][37][38][39][40][41][42] and differential-aperture x-ray diffraction microscopy (DAXM). [43][44][45][46][47][48][49][50] DAXM enables 3D OM by using a focused polychromatic x-ray beam, scanning a ...…”

Observation of Bulk Plasticity in a Polycrystalline Titanium Alloy by Diffraction Contrast Tomography and Topotomography

“…Note that in situ testing (not reported here) requires an optimized design of the load frame [36] and of the detector head in order to maintain such short propagation distances. Also note that in for future experiments, acquisitions with different propagation distances provide additional constraints which can improve the convergence of the iterative optimization algorithms used for reconstructing the local orientation field inside a grain [53].…”

“…For instance Figure 5b shows the orientation spread plots for grain 699 obtained with reflections (1 0 1 1) and (1 1 2 2) and one can see that the results are in very good agreement. Using several reflections will be useful in the future when extracting the orientation field from the measurements [53] (not done in this paper).…”

“…Since TT can not resolve lattice rotations around the probed scattering vector, the inversion has to include complementary grain projection data from DCT. This is in principle feasible using iterative approaches as demonstrated in [53] or by adapting the forward modeling strategy developed by [25] to the combined DCT and TT acquisition geometry. As the topotomography geometry is more complex (it involves several rotations around the eucentric point), the sensitivity and spatial resolution of this approach may suffer from diffractometer error motion and requires an accurate calibration of the instrument geometry.…”

3D Orientation Imaging of Polymer Chains with Polarization-Controlled Coherent Raman Microscopy

“…Various diffraction-based imaging methods have been developed to map the molecular orientation in spatially heterogeneous materials. X-ray diffraction-based techniques have been used to map the orientations of separate crystallite domains in polycrystalline materials. , However, X-ray tomographic imaging approaches are limited to studying highly crystalline samples with a thickness of at least tens of micrometers, and spatial resolution is limited to several micrometers. Due to weak scattering cross section, X-ray-based orientational imaging of organic materials requires a synchrotron source, which is not readily available.…”