Bridging Grain Mapping and Dark Field X-ray Microscopy for Multiscale Diffraction Imaging

TL;DR

This paper presents a unified, non-destructive workflow combining grain-mapping and dark field X-ray microscopy to image lattice defects within polycrystalline materials across multiple scales, enabling detailed defect analysis.

Contribution

A transferable framework that integrates mesoscale grain mapping with high-resolution defect imaging using open-source software, facilitating multiscale diffraction imaging without sample reorientation.

Findings

Rapid calculation of DFXM motor positions for all grains

Reproducible zooming from millimetre-scale to dislocation-level imaging

Direct visualization of misorientation fields across grain boundaries

Abstract

Resolving how defects emerge and interact within the hierarchical structure of polycrystalline materials remains a core challenge in materials science. Grain-mapping methods such as three-dimensional X-ray diffraction (3DXRD) and diffraction contrast tomography (DCT) provide essential mesoscale context but lack the resolution to image lattice defects. Conversely, high-resolution methods like Dark Field X-ray Microscopy (DFXM) capture lattice distortions but not the surrounding microstructure. Here, we introduce a transferable framework that unifies these complementary approaches into a single, non-destructive workflow. Enabled by open-source software, the method translates grain orientation and position data into precise goniometer settings for DFXM imaging without dismounting or reorienting the sample. Applied to an iron polycrystal containing 1100 grains, DFXM motor positions were calculated for all grains within seconds, enabling on-the-fly targeting of specific grains. This allows reproducible zooming from the millimetre-scale aggregate to individual dislocations. We resolve three-dimensional misorientation fields across grain boundaries with 36 nm pixel size, directly capturing grain-grain interactions within their microstructural context. Finally, we show transferability from LabDCT to synchrotron and XFEL platforms, enabling new ways of studying defect interactions across scales.