scholarly journals High-Energy X-Ray Diffraction Microscopy in Materials Science

2020 ◽  
Vol 50 (1) ◽  
pp. 395-436 ◽  
Author(s):  
Joel V. Bernier ◽  
Robert M. Suter ◽  
Anthony D. Rollett ◽  
Jonathan D. Almer

High-energy diffraction microscopy (HEDM) is an implementation of three-dimensional X-ray diffraction microscopy. HEDM yields maps of internal crystal orientation fields, strain states, grain shapes and locations as well as intragranular orientation distributions, and grain boundary character. Because it is nondestructive in hard materials, notably metals and ceramics, HEDM has been used to study responses of these materials to external fields including high temperature and mechanical loading. Currently available sources and detectors lead to a spatial resolution of ∼1 μm and an orientation resolution of <0.1○. With the penetration characteristic of high energies ( E ≥ 50 keV), sample cross-section dimensions of ∼1 mm can be studied in materials containing elements across much of the Periodic Table. This review describes hardware and software associated with HEDM as well as examples of applications. These applications include studies of grain growth, recrystallization, texture development, orientation gradients, deformation twinning, annealing twinning, plastic deformation, and additive manufacturing. We also describe relationships to other X-ray-based methods as well as prospects for further development.

2015 ◽  
Vol 48 (4) ◽  
pp. 1165-1171 ◽  
Author(s):  
E. Wielewski ◽  
D. B. Menasche ◽  
P. G. Callahan ◽  
R. M. Suter

Near-field high-energy X-ray diffraction microscopy has been used to characterize the three-dimensional (3-D) crystallographic orientation field of the hexagonal close-packed α phase in a bulk Ti–6Al–4V specimen with a lamellar (β-annealed) microstructure. These data have been segmented using a 3-D misorientation-based grain finding algorithm, providing unprecedented information about the complex 3-D morphologies and spatial misorientation distributions of the transformed α lamella colonies. A 3-D Burgers orientation relationship-based flood-fill algorithm has been implemented to reconstruct the morphologies and crystallographic orientations of the high-temperature body-centered cubic prior-β grains. The combination of these data has been used to gain an understanding of the role of the prior-β grain structure in the formation of specific morphologies and spatial misorientation distributions observed in the transformed α colony structures. It is hoped that this understanding can be used to develop transformation structures optimized for specific applications and to produce more physically realistic synthetic microstructures for use in simulations.


2012 ◽  
Vol 715-716 ◽  
pp. 447-454 ◽  
Author(s):  
C. M. Hefferan ◽  
S. F. Li ◽  
J. Lind ◽  
Ulrich Lienert ◽  
Anthony D. Rollett ◽  
...  

We have used high energy x-ray diffraction microscopy (HEDM) to study annealing behavior in high purity aluminum. In-situ measurements were carried out at Sector 1 of the Advanced Photon Source. The microstructure in a small sub-volume of a 1 mm diameter wire was mapped in the as-received state and after two differential anneals. Forward modeling analysis reveals three dimensional grain structures and internal orientation distributions inside grains. The analysis demonstrates increased ordering with annealing as well as persistent low angle internal boundaries. Grains that grow from disordered regions are resolution limited single crystals. Together with this recovery behavior, we observe subtle motions of some grain boundaries due to annealing.


MRS Bulletin ◽  
2004 ◽  
Vol 29 (3) ◽  
pp. 166-169 ◽  
Author(s):  
Henning F. Poulsen ◽  
Dorte Juul Jensen ◽  
Gavin B.M. Vaughan

AbstractThree-dimensional x-ray diffraction (3DXRD) microscopy is a tool for fast and nondestructive characterization of the individual grains, subgrains, and domains inside bulk materials. The method is based on diffraction with very penetrating hard x-rays (E ≥ 50 keV), enabling 3D studies of millimeter-to-centimeter-thick specimens.The position, volume, orientation, and elastic and plastic strain can be derived for hundreds of grains simultaneously. Furthermore, by applying novel reconstruction methods, 3D maps of the grain boundaries can be generated. The 3DXRD microscope in use at the European Synchrotron Radiation Facility in Grenoble, France, has a spatial resolution of ∼5 μm and can detect grains as small as 150 nm. The technique enables, for the first time, dynamic studies of the individual grains within polycrystalline materials. In this article, some fundamental materials science applications of 3DXRD are reviewed: studies of nucleation and growth kinetics during recrystallization, recovery, and phase transformations, as well as studies of polycrystal deformation.


2012 ◽  
Vol 45 (6) ◽  
pp. 1084-1097 ◽  
Author(s):  
Henning Friis Poulsen

Three-dimensional X-ray diffraction microscopy is a fast and nondestructive structural characterization technique aimed at studies of the individual crystalline elements (grains or subgrains) within millimetre-sized polycrystalline specimens. It is based on two principles: the use of highly penetrating hard X-rays from a synchrotron source and the application of `tomographic' reconstruction algorithms for the analysis of the diffraction data. In favourable cases, the position, morphology, phase and crystallographic orientation can be derived for up to 1000 elements simultaneously. For each grain its average strain tensor may also be derived, from which the type II stresses can be inferred. Furthermore, the dynamics of the individual elements can be monitored during typical processes such as deformation or annealing. A review of the field is provided, with a viewpoint from materials science.


2018 ◽  
Vol 74 (5) ◽  
pp. 425-446 ◽  
Author(s):  
Ashley Nicole Bucsek ◽  
Darren Dale ◽  
Jun Young Peter Ko ◽  
Yuriy Chumlyakov ◽  
Aaron Paul Stebner

Modern X-ray diffraction techniques are now allowing researchers to collect long-desired experimental verification data sets that are in situ, three-dimensional, on the same length scales as critical microstructures, and using bulk samples. These techniques need to be adapted for advanced material systems that undergo combinations of phase transformation, twinning and plasticity. One particular challenge addressed in this article is direct analysis of martensite phases in far-field high-energy diffraction microscopy experiments. Specifically, an algorithmic forward model approach is presented to analyze phase transformation and twinning data sets of shape memory alloys. In the present implementation of the algorithm, the crystallographic theory of martensite (CTM) is used to predict possible martensite microstructures (i.e. martensite orientations, twin mode, habit plane, twin plane and twin phase fractions) that could form from the parent austenite structure. This approach is successfully demonstrated on three single- and near-single-crystal NiTi samples where the fundamental assumptions of the CTM are not upheld. That is, the samples have elastically strained lattices, inclusions, precipitates, subgrains, R-phase transformation and/or are not an infinite plate. The results indicate that the CTM still provides structural solutions that match the experiments. However, the widely accepted maximum work criterion for predicting which solution of the CTM should be preferred by the material does not work in these cases. Hence, a more accurate model that can simulate these additional structural complexities can be used within the algorithm in the future to improve its performance for non-ideal materials.


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