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The deformation-related microstructure of an Indian Ocean zircon hosted in a gabbro deformed at amphibolitegrade has been quantified by electron backscatter diffraction. Orientation mapping reveals progressive variations in intragrain crystallographic orientations that accommodate 20° of misorientation in the zircon crystal. These variations are manifest by discrete low-angle (<4º) boundaries that separate domains recording no resolvable orientation variation. The progressive nature of orientation change is documented by crystallographic pole Zircon (ZrSiO 4) is an extremely significant accessory phase due to its ability to incorporate and retain geologically important trace and rare earth elements (REE), including elements produced by radioactive decay. These characteristics enable the geochemistry of zircon to be applied to a wide range of geoscience disciplines, for example rock petrogenesis (Belousova

During plastic deformation of metals and alloys, dislocations arrange in ordered patterns. How and when these self-organization processes take place have remained elusive, because in situ observations have not been feasible. We present an x-ray diffraction method that provided data on the dynamics of individual, deeply embedded dislocation structures. During tensile deformation of pure copper, dislocation-free regions were identified. They showed an unexpected intermittent dynamics, for example, appearing and disappearing with proceeding deformation and even displaying transient splitting behavior. Insight into these processes is relevant for an understanding of the strength and work-hardening of deformed materials.

Many physical and mechanical properties of crystalline materials depend strongly on their internal structure, which is typically organized into grains and domains on several length scales. Here we present dark-field X-ray microscopy; a non-destructive microscopy technique for the three-dimensional mapping of orientations and stresses on lengths scales from 100 nm to 1 mm within embedded sampling volumes. The technique, which allows ‘zooming’ in and out in both direct and angular space, is demonstrated by an annealing study of plastically deformed aluminium. Facilitating the direct study of the interactions between crystalline elements is a key step towards the formulation and validation of multiscale models that account for the entire heterogeneity of a material. Furthermore, dark-field X-ray microscopy is well suited to applied topics, where the structural evolution of internal nanoscale elements (for example, positioned at interfaces) is crucial to the performance and lifetime of macro-scale devices and components thereof.

How would you… …describe the overall significance of this paper? This paper describes emerging characterization experiments referred to as High Energy Diffraction Microscopy conducted at the Advanced Photon Source (APS) beam line 1-ID-C. "Near field" diffraction is used to quantify three-dimensional orientation maps of polycrystalline samples non-destructively, with incredible detail grain boundary geometry. "Far field" experiments are used to quantify lattice strains and single crystal stress states within large aggregates subjected to in situ loading. …describe this work to a materials science and engineering professional with no experience in your technical specialty? Materials derive their mechanical properties from their internal structure. As engineering moves downscale, it becomes more important to quantify the structure and mechanical response of engineering materials on small size scales. High energy x-ray diffraction methods are rapidly evolving into important microscale characterization tools that can be used together with high fidelity mechanical models. …describe this work to a layperson? Micro-and nano-engineering methods hold enormous promise for a broad spectrum of products and processes. The determination of material attributes and mechanical properties on small size scales is one of the main barriers to moving down scale. Instead of making tiny specimens, we examine deforming test samples using high energy x-rays, created using a special national laboratory facility. This work will enable us to precisely reconstruct the internal structure of engineering alloys and will provide important mechanical data on the micron scale. The status of the High Energy Diffraction Microscopy (HEDM) program at the 1-ID beam line of the Advanced Photon Source is reported. HEDM applies high energy synchrotron radiation for the grain and sub-grain scale structural and mechanical characterization of polycrystalline bulk materials in situ during thermomechanical loading. Case studies demonstrate the mapping of grain boundary topology, the evaluation of stress tensors of individual grains during tensile deformation and comparison to a finite element modeling simulation, and the characterization of evolving dislocation structure. Complementary information is obtained by post mortem electron microscopy on the same sample volume previously investigated by HEDM.