Diffraction/scattering computed tomography for three-dimensional characterization of multi-phase crystalline and amorphous materials

2012 ◽  
Vol 45 (6) ◽  
pp. 1109-1124 ◽  
Author(s):  
M. Álvarez-Murga ◽  
P. Bleuet ◽  
J.-L. Hodeau
Keyword(s):  
Computed Tomography ◽  
Amorphous Materials ◽  
Materials Science ◽  
Three Dimensional ◽  
Diffraction Scattering ◽  
Amorphous Phases ◽  
The Matrix ◽  
Local Patterns ◽  
Structural Image ◽  
Multi Phase

The three-dimensional characterization method described herein is based on diffraction and scattering techniques combined with tomography and uses the variation of these signals to reconstruct a two-dimensional/three-dimensional structural image. To emphasize the capability of the method in discriminating between different poorly ordered phases, it is named diffraction/scattering computed tomography (DSCT). This combination not only allows structural imaging but also yields an enhancement of the weak signals coming from minor phases, thereby increasing the sensitivity of structural probes. This article reports the suitability of the method for discrimination of polycrystalline and amorphous phases and for extraction of their selective local patterns with a contrast sensitivity of about 0.1% in weight of minor phases relative to the matrix. The required background in tomography is given and then the selectivity of scattering signal, the efficiency of the method, reconstruction artefacts and limitations are addressed. The approach is illustrated through different examples covering a large range of applications based on recent literature, showing the potential of DSCT in crystallography and materials science, particularly when functional and/or precious samples with sub-micrometre features have to be investigated in a nondestructive way.

scholarly journals Diffraction/Scattering Tomography on multi-phase crystalline/amorphous materials

2014 ◽  
Vol 70 (a1) ◽  
pp. C139-C139 ◽  
Author(s):  
Michelle Alvarez-Murga ◽  
Pierre Bleuet ◽  
Christophe Lepoittevin ◽  
Nathalie Boudet ◽  
Gaston Gabarino ◽  
...  
Keyword(s):  
Amorphous Materials ◽  
Structural Information ◽  
Local Variation ◽  
X Rays ◽  
Complex Materials ◽  
Diffraction Scattering ◽  
Invasive Approach ◽  
Non Invasive ◽  
Phase Selectivity ◽  
Multi Phase

By suitably combining diffraction/scattering and tomography (DSCT), it is possible to access to selective submicron 2D/3D structural and micro-structural information, which cannot be obtained from separate, independent diffraction and tomography experiments. DSCT is used to discriminate between multi-phase crystalline and amorphous materials, especially when the similarities in densities limit the use of other methods. In addition, this method is sensitive to local variation of the crystalline state, texture, grain size or strains inside the object and can allow simultaneous 3D mappings of such properties. The DSCT phase-selectivity can be easily combined with fluorescence and absorption for added chemical and density resolution allowing multi-modal analyses. As samples can be used in their original state, this method can be applied without cutting or polishing them. Moreover the setup can be adapted with specific sample environments in order to monitor phase and microstructure evolution as a function of an externally controlled parameter with a non-invasive approach. After a first report on in 1998 [1], since 2008 capabilities of DSCT have been demonstrated using x-rays on complex materials as diverse as biological tissue, pigments, Portland cements, Carbon-based materials, Uranium-based nuclear fuel, Ni/Al2O3 catalysts or amorphous systems [2]. More recently, the technique has evolved towards quantitative characterization of the microstructure and stress/strain through either Rietveld or Peak Profile analyses and also pair distribution function techniques (PDF) and their application to nanostructured materials [3]. In this poster contribution, we briefly review the principle and methodology of pencil-beam based x-ray DSCT which is two-fold: (i) selective structural imaging and (ii) extraction of selective scattered patterns of ultra-minor phases.

scholarly journals Investigation of Fatigue Behavior of Three Dimensional Interlock Composites by Time-Lapse Micro-Computed Tomography

2021 ◽  
Vol 6 (1) ◽  
pp. 14
Author(s):  
Christophe Cruanes ◽  
Keerthi Krishna Parvathaneni ◽  
Dmytro Vasiukov ◽  
Chung Hae Park
Keyword(s):  
Computed Tomography ◽  
Fatigue Behavior ◽  
Three Dimensional ◽  
Injection Pressure ◽  
Fatigue Loading ◽  
Time Lapse ◽  
Fatigue Performance ◽  
Micro Computed Tomography ◽  
The Matrix ◽  
Micro Tomography

The mechanism of the crack propagation in three dimensional (3D) glass-fiber warp interlock epoxy composites under fatigue loading was investigated via time-lapse micro-computed tomography (µCT) observations. Two different composite samples were manufactured by means of a resin transfer molding (RTM) process under two different constant injection pressure conditions to generate intrayarn and interyarn voids separately. Fatigue loads were applied by blocks of 105 cycles and followed by µCT measurements. Regions of interest for micro tomography scans were selected based on hot spots detected by infrared thermography. After the analysis of the obtained data, it was observed that detectable cracks were generally initiated by debonding in the zone between two adjacent warp yarns and grew along their interface. Then, these cracks propagated along one of the warp yarns aligned in the loading direction while remaining in the middle of the specimen cross-section. The coalescence of the cracks and further propagation to the weakest zones were observed around and after the middle lifetime. Finally, we demonstrated the influence of the void defects at different material scales. I was found that interyarn voids have relatively little influence on the fatigue performance whereas they can, sometimes, attract and deviate cracks in the matrix zone between adjacent yarns. It was also shown that the intrayarn voids are crucial to degenerate the fatigue performance of the yarns at the micro-scale.

Concurrent determination of nanocrystal shape and amorphous phases in complex materials by diffraction scattering computed tomography

2017 ◽  
Vol 50 (1) ◽  
pp. 192-197 ◽  
Author(s):  
Mie Elholm Birkbak ◽  
Ida Gjerlevsen Nielsen ◽  
Simon Frølich ◽  
Stuart R. Stock ◽  
Peter Kenesei ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Functional Materials ◽  
Multivariate Curve Resolution ◽  
Complete Analysis ◽  
Wide Angle ◽  
Diffraction Scattering ◽  
Energy Devices ◽  
Amorphous Phases ◽  
Nano Crystalline ◽  
Angle Scattering

Advanced functional materials often contain multiple phases which are (nano)crystalline and/or amorphous. The spatial distribution of these phases and their properties, including nanocrystallite size and shape, often drives material function yet is difficult to obtain with current experimental techniques. This article describes the use of diffraction scattering computed tomography, which maps wide-angle scattering information onto sample space, to address this challenge. The wide-angle scattering signal contains information on both (nano)crystalline and amorphous phases. Rietveld refinement of reconstructed diffraction patterns is employed to determine anisotropic nanocrystal shapes. The background signal from refinements is used to identify contributing amorphous phases through multivariate curve resolution. Thus it is demonstrated that reciprocal space analysis in combination with diffraction scattering computed tomography is a very powerful tool for the complete analysis of complex multiphase materials such as energy devices.

X-ray microtomography

1988 ◽  
Vol 46 ◽  
pp. 998-999
Author(s):  
H.W. Deckman ◽  
B.F. Flannery ◽  
J.H. Dunsmuir ◽  
K.D' Amico
Keyword(s):  
Computed Tomography ◽  
Internal Structure ◽  
Imaging Technique ◽  
Three Dimensional ◽  
Tissue Structure ◽  
Individual Element ◽  
X Ray ◽  
Non Invasive ◽  
Panoramic Imaging ◽  
Three Dimensional Images

We have developed a new X-ray microscope which produces complete three dimensional images of samples. The microscope operates by performing X-ray tomography with unprecedented resolution. Tomography is a non-invasive imaging technique that creates maps of the internal structure of samples from measurement of the attenuation of penetrating radiation. As conventionally practiced in medical Computed Tomography (CT), radiologists produce maps of bone and tissue structure in several planar sections that reveal features with 1mm resolution and 1% contrast. Microtomography extends the capability of CT in several ways. First, the resolution which approaches one micron, is one thousand times higher than that of the medical CT. Second, our approach acquires and analyses the data in a panoramic imaging format that directly produces three-dimensional maps in a series of contiguous stacked planes. Typical maps available today consist of three hundred planar sections each containing 512x512 pixels. Finally, and perhaps of most import scientifically, microtomography using a synchrotron X-ray source, allows us to generate maps of individual element.

Designing TIMP (tissue inhibitor of metalloproteinases) variants that are selective metalloproteinase inhibitors

2003 ◽  
Vol 70 ◽  
pp. 201-212 ◽  
Author(s):  
Hideaki Nagase ◽  
Keith Brew
Keyword(s):  
Three Dimensional ◽  
Therapeutic Interventions ◽  
Tissue Inhibitors Of Metalloproteinases ◽  
Structural Basis ◽  
Structural Elements ◽  
Ridge Structure ◽  
Extracellular Matrix Components ◽  
Metalloproteinase Inhibitors ◽  
The Matrix ◽  
A Disintegrin And Metalloproteinase

The tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors of the matrix metalloproteinases (MMPs), enzymes that play central roles in the degradation of extracellular matrix components. The balance between MMPs and TIMPs is important in the maintenance of tissues, and its disruption affects tissue homoeostasis. Four related TIMPs (TIMP-1 to TIMP-4) can each form a complex with MMPs in a 1:1 stoichiometry with high affinity, but their inhibitory activities towards different MMPs are not particularly selective. The three-dimensional structures of TIMP-MMP complexes reveal that TIMPs have an extended ridge structure that slots into the active site of MMPs. Mutation of three separate residues in the ridge, at positions 2, 4 and 68 in the amino acid sequence of the N-terminal inhibitory domain of TIMP-1 (N-TIMP-1), separately and in combination has produced N-TIMP-1 variants with higher binding affinity and specificity for individual MMPs. TIMP-3 is unique in that it inhibits not only MMPs, but also several ADAM (a disintegrin and metalloproteinase) and ADAMTS (ADAM with thrombospondin motifs) metalloproteinases. Inhibition of the latter groups of metalloproteinases, as exemplified with ADAMTS-4 (aggrecanase 1), requires additional structural elements in TIMP-3 that have not yet been identified. Knowledge of the structural basis of the inhibitory action of TIMPs will facilitate the design of selective TIMP variants for investigating the biological roles of specific MMPs and for developing therapeutic interventions for MMP-associated diseases.

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