I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[37837, 33810]
Open Access
Abstract: Multilayer braided composite tubes are widely used in torsion-critical structures, yet their damage behaviour remains insufficiently understood. Here, we investigate vacuum-infused single-, double- and triple-layer ±45° diamond-braided carbon fibre/epoxy tubes under torsion using in-situ, time-resolved synchrotron X-ray computed tomography. Increasing the number of layers promotes inter-layer nesting and modifies the mesoscale architecture, producing a through-thickness variation in fibre volume fraction and a reduction in tow crimp from the inner to the outer layers. Although the effective shear modulus changes only marginally (∼8.2–8.5 GPa), the shear strain at damage initiation increases from ∼0.5% in single-layer tubes to ∼0.75% and ∼1.0% in double- and triple-layer tubes, respectively. Damage in the double- and triple-layer tubes is dominated by inter-layer and inter-tow debonding, whereas single-layer tubes show predominantly intra-tow cracking. Microscale fibre buckling/kinking is also delayed in the multilayer tubes, consistent with the through-thickness tow-crimp gradient and additional lateral confinement. The multilayer tubes further exhibit a more stable post-peak response, with no pronounced load drops in the load–displacement curves. Overall, these observations show that changing the number of braided layers substantially alters the mesoscale tow architecture and, in turn, governs the torsional damage response of braided composite tubes.
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Aug 2026
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I13-2-Diamond Manchester Imaging
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Dongze
He
,
Yuan
Chai
,
Jiduo
Zhang
,
Mohammad
Islam
,
Leonard
Turpin
,
Kaz
Wanelik
,
Valeriy
Titarenko
,
Elizabeth E.
Evans
,
Zihan
Song
,
Timothy L.
Burnett
,
Kali Babu
Katnam
,
Prasad
Potluri
,
Philip J.
Withers
Diamond Proposal Number(s):
[37837, 33810]
Open Access
Abstract: The aim of this study was to examine the extent to which different resin infiltration processes can lead to different architectures and hence different mechanical properties in braided composites based on the same textile preforms (i.e. having the same fibre content). To this end single-layer carbon/epoxy (±45°) braided tubes have been manufactured vacuum assisted resin infusion using: (a) resin transfer moulding (RTM) with rigid inner and outer moulds, and (b) vacuum infusion (VI) with a rigid inner mould, but with a flexible outer mould. Their 3D architecture and the resulting torsional behaviour has then been investigated by in-situ synchrotron X-ray CT and image-based finite element modelling. The VI process gave a significantly reduced the tube wall thickness (∼35%) relative to RTM, higher effective fibre volume fraction (∼55% VI vs ∼33% RTM) and flatter (half-lenticular) tow geometries with greater in- and out-of-plane crimp and higher crossover density. Taken together these differences in mesoscale architecture led to the VI braided tube exhibiting ∼16% higher shear modulus yet ∼30% lower torsional rigidity compared to the RTM specimens. Image-based modelling showed that the flattened tows and increased crimp angles in the VI braided tubes amplified the local stresses, leading to earlier damage initiation (∼0.5% shear strain) and intra-tow cracking. More widely this study exemplifies how different resin infiltration processes can lead to different post-cure fibre architectures and mechanical performance, even when based on the same textile preform.
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May 2026
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I12-JEEP: Joint Engineering, Environmental and Processing
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Jiaqi
Xu
,
Xun
Zhang
,
Jack M.
Donoghue
,
Albert D.
Smith
,
Rahul
Unnikrishnan
,
Rhys
Thomas
,
Vahid
Nekouie
,
Jie
Luo
,
Dongchen
Hu
,
Michael
Preuss
,
Philip J.
Withers
Diamond Proposal Number(s):
[28853]
Open Access
Abstract: Some alloys are difficult to make by ingot metallurgy. Here, the potential for making alloys by hot isostatic pressing (HIPing) and homogenising powder mixtures is explored for Ti–Fe. Iron is an effective and cost-effective β stabiliser but gives rise to segregation issues during solidification. Exploiting the fact that Fe diffusion through Ti is fast, Fe and Ti powders are co-HIPed at, and homogenised at, only 800°C in order to create an α+β microstructure based on small prior β grains. The evolution of phase composition and elemental distribution during homogenisation has been tracked quantitatively in 3D by X-ray computed tomography and in 2D by energy dispersive spectroscopy and electron backscatter diffraction. The final homogenised microstructure consists of fine α Ti laths separated by β ligaments with a prior β grain size of only 80 μm, free of TiFe intermetallics with no indication of a grain boundary α constituent. Kirkendall pore formation was observed during homogenisation heat treatment due to the fast diffusion of Fe in Ti. This study shows the potential of HIP processing followed by homogenisation heat treatment as a novel solid-state manufacturing route for difficult-to-cast alloys.
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Apr 2026
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[30413]
Abstract: The migration and deposition of fine particles in porous materials is critical in industries such as energy, pharmaceuticals, and environmental engineering. Using 3D time-lapse synchrotron X-ray imaging, we observe fine particles invading porous media, analyzing the effects of pore size and heterogeneity at both pore and macro scales. Glass beads model homogeneous and heterogeneous conditions, revealing a sequence of deposition processes: surface attachment, throat bridging, blocking, pore filling, compaction, and migration. A critical throat-to-particle size ratio of 1.7 governs deposition behavior. At the macro-scale, heterogeneities like beddings and flow pathways influence fines migration and deposition. Based on dynamic 3D imaging, we propose a mechanism for fines behavior in heterogeneous porous media. These findings enhance understanding of fines migration, offering a predictive framework for managing formation damage and optimizing filter cake design in drilling and clean energy applications.
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Mar 2025
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I15-Extreme Conditions
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Ji
Hu
,
Alexander G.
Squires
,
Jędrzej
Kondek
,
Arthur B.
Youd
,
Pooja
Vadhva
,
Michael
Johnson
,
Partha P
Paul
,
Philip J.
Withers
,
Marco
Di Michiel
,
Dean S.
Keeble
,
Michael Ryan
Hansen
,
David O.
Scanlon
,
Alexander J. E.
Rettie
Diamond Proposal Number(s):
[35411]
Open Access
Abstract: Lithium phosphides are an emerging class of Li+ ion conductors for solid state battery applications. Despite potentially favorable characteristics as a solid electrolyte, stoichiometric crystalline Li3AlP2 has been reported to be an ionic insulator. Using a combined computational and experimental approach, we investigate the underlying reasons for this and show that ion transport can be induced via defects and structural disorder in this material. Lithium vacancies are shown to promote diffusion, and a low barrier to Li+ hopping of 0.2-0.3 eV is revealed by both simulations and experiment. However, polycrystalline pellets exhibit low ionic conductivity (≈10−8 S cm−1) at room temperature, attributed to crystalline anisotropy and the presence of resistive grain boundaries. These aspects can be overcome in nanocrystalline Li3AlP2, where ionic conductivity values approaching 10−6 S cm−1 and low electronic conductivities are achieved. This approach, leveraging both defects and structural disorder, should have relevance to the discovery of new, or previously overlooked, ion conducting materials.
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Jan 2025
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[31620]
Open Access
Abstract: Short-fibre thermoplastic composites offer a balance between cost, processability, and performance, as well as providing a use for recycled fibres making them attractive in various industrial applications. However, the fibres tend to be misaligned due to their low aspect ratio, which can impact mechanical performance. This work examines the as-manufactured microstructure of a chopped carbon fibre-reinforced nylon composite made by material extrusion additive manufacturing in terms of fibre misalignment, void content, shape and distribution before going on to determine its effect on damage evolution under tensile straining by in-situ time-lapse synchrotron computed tomography (CT). To this end, CT scans have been acquired at various stages throughout straining. A high degree of fibre alignment is observed with
86% within 14
of the extrusion axis, giving a Krenchel orientation factor of 0.75. The time-lapse CT image sequence reveals that because the mean fibre length (
.) is below the critical fibre length fibre fracture does not take place during plastic straining. Instead, failure occurs during straining from pre-existing voids and newly nucleated ones mainly located at fibre ends, their growth and coalescence. The experimental elastic modulus and strength are compared against the Cox-Krenchel and Kelly-Tyson analytical models that take into account fibre misalignment and length, which demonstrates that the fibre orientation is sufficient and future improvements in properties could be achieved by reducing the initial void content (
2.3%) and increasing the length and volume fraction of the reinforcing fibres.
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Dec 2024
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I15-Extreme Conditions
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Diamond Proposal Number(s):
[8699]
Open Access
Abstract: The mechanisms contributing to the electromechanical response of piezoelectric ceramics in shear mode have been investigated using high energy synchrotron x-ray diffraction. Soft lead zirconate titanate ceramic specimens were subjected to an electric field in the range 0.2 to 3.0 MV m-1, perpendicular to that of the initial poling direction, while XRD patterns were recorded in transmission. At low electric field levels, the axial strains remained close to zero but a significant shear strain occurred due to the reversible shear-mode piezoelectric coefficient. Both the axial and shear strains increased substantially at higher field levels due to irreversible ferroelectric domain switching. Eventually, the shear strain decreased again as the average remanent polarization became oriented towards the electric field direction. The lattice strain and domain orientation distributions follow the form of the total strain tensor, enabling the domain switching processes to be monitored by the rotation of the principal strain axis. Reorientation of this axis towards the electric field direction occurred progressively above 0.6 MV m-1, while the angle of rotation increased from 0° to approximately 80° at the maximum field of 3.0 MV m-1. A strong correlation was established between the effective strains associated with different crystallographic directions, which was attributed to the effects of elastic coupling between grains in the polycrystal.
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Nov 2024
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[13234]
Open Access
Abstract: In situ synchrotron radiation X-ray computed tomography (CT) is used to understand the void nucleation and growth behaviour of dual phase (DP) steel, DP800, during uniaxial tensile deformation. The voids were identified post mortem as having nucleated primarily in the (41 vol%) martensite phase. The behaviour of individual voids was found to be broadly in line with a Rice and Tracey style growth model (their volume increasing by a factor of 10), while the mean void size was broadly in line with a model that included the continuous nucleation of new voids, as well as the growth of existing voids, throughout straining. Voids tended to elongate during uniaxial (low triaxiality) straining, but then to dilate more isotropically as necking led to increased triaxiality. One large pre-existing void was found to elongate quicky at first, but then for growth to slow, presumably because it was not located in the highest triaxial stress (necked) region. Perhaps surprisingly the average size of the void population grows only slowly (by a factor of 2) during straining; this is because while the size of each void grows, new small voids are always being nucleated. Finally, the changes of stress triaxiality and shear stress state during tensile deformation of the square cross-section smooth tensile specimen are investigated via finite element modelling, to qualitatively assess the impact of sample geometry on void nucleation behaviour and fracture strain in the current study.
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Nov 2023
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Ralf F.
Ziesche
,
Thomas M. M.
Heenan
,
Pooja
Kumari
,
Jarrod
Williams
,
Weiqun
Li
,
Matthew E.
Curd
,
Timothy L.
Burnett
,
Ian
Robinson
,
Dan J. L.
Brett
,
Matthias J.
Ehrhardt
,
Paul D.
Quinn
,
Layla B.
Mehdi
,
Philip J.
Withers
,
Melanie
Britton
,
Nigel D.
Browning
,
Paul R.
Shearing
Open Access
Abstract: Demand for low carbon energy storage has highlighted the importance of imaging techniques for the characterization of electrode microstructures to determine key parameters associated with battery manufacture, operation, degradation, and failure both for next generation lithium and other novel battery systems. Here, recent progress and literature highlights from magnetic resonance, neutron, X-ray, focused ion beam, scanning and transmission electron microscopy are summarized. Two major trends are identified: First, the use of multi-modal microscopy in a correlative fashion, providing contrast modes spanning length- and time-scales, and second, the application of machine learning to guide data collection and analysis, recognizing the role of these tools in evaluating large data streams from increasingly sophisticated imaging experiments.
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May 2023
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I13-2-Diamond Manchester Imaging
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Clara
Anduix-Canto
,
Mark A.
Levenstein
,
Yi-Yeoun
Kim
,
Jose R. A.
Godinho
,
Alexander N.
Kulak
,
Carlos
Gonzalez Nino
,
Philip J.
Withers
,
Jonathan P.
Wright
,
Nikil
Kapur
,
Hugo K.
Christenson
,
Fiona C.
Meldrum
Diamond Proposal Number(s):
[13578, 17314]
Open Access
Abstract: Characterizing the pathways by which crystals form remains a significant challenge, particularly when multiple pathways operate simultaneously. Here, an imaging-based strategy is introduced that exploits confinement effects to track the evolution of a population of crystals in 3D and to characterize crystallization pathways. Focusing on calcium sulfate formation in aqueous solution at room temperature, precipitation is carried out within nanoporous media, which ensures that the crystals are fixed in position and develop slowly. The evolution of their size, shape, and polymorph can then be tracked in situ using synchrotron X-ray computed tomography and diffraction computed tomography without isolating and potentially altering the crystals. The study shows that bassanite (CaSO4 0.5H2O) forms via an amorphous precursor phase and that it exhibits long-term stability in these nanoscale pores. Further, the thermodynamically stable phase gypsum (CaSO4 2H2O) can precipitate by different pathways according to the local physical environment. Insight into crystallization in nanoconfinement is also gained, and the crystals are seen to grow throughout the nanoporous network without causing structural damage. This work therefore offers a novel strategy for studying crystallization pathways and demonstrates the significant impact of confinement on calcium sulfate precipitation, which is relevant to its formation in many real-world environments.
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Sep 2021
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