I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[26730]
Open Access
Abstract: Hydrogen (H2) storage in porous geological formations offers a promising means to balance supply and demand in the renewable energy sector, supporting the energy transition. Important unknowns to this technology include the H2 fluid flow dynamics through the porous medium which affect H2 injectivity and recovery. We used time-resolved X-ray computed microtomography to image real-time unsteady and steady state injections of H2 and brine (2 M KI) into a Clashach sandstone core at 5 MPa and ambient temperature. In steady state injections, H2 entered the brine-saturated rock within seconds, dispersing over several discrete pores. Over time, some H2 ganglia connected, disconnected and then reconnected from each other (intermittent flow), indicating that the current presumption of a constant connected flow pathway during multiphase fluid flow is an oversimplification. Pressure oscillations at the sample outlet were characterized as red noise, supporting observations of intermittent pore-filling. At higher H2 fractional flow the H2 saturation in the pore space increased from 20-22 % to 28 %. Average Euler characteristics were generally positive over time at all H2 flow fractions, indicating poorly connected H2 clusters and little control of connectivity on the H2 saturation. In unsteady state injections, H2 displaced brine in sudden pore-filling events termed Haines jumps, which are key to understanding fluid dynamics in porous media. Our results suggest a lower H2 storage capacity in sandstone aquifers with higher injection-induced hydrodynamic flow and suggest a low H2 recovery. For more accurate predictions of H2 storage potential and recovery, geological models should incorporate energy-dissipating processes such as Haines jumps.
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Apr 2025
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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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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[37256]
Open Access
Abstract: he high brilliance and coherence of light generated at synchrotron facilities make synchrotron X-ray imaging an invaluable tool for the non-destructive analysis of samples across a range of interdisciplinary sciences. For samples with low attenuation contrast, phase-contrast imaging and phase-retrieval techniques can be used to enhance image contrast and provide complementary phase-shift information. In this work, we demonstrate the phase-contrast imaging capabilities of the Diamond Light Source I12-JEEP beamline using two samples: a fly encased in 4 mm of steel, and a lower chicken leg (drumstick) bones with surrounding soft tissue. Techniques such as X-ray phase-contrast imaging, near-field speckle-based phase-contrast tomography and propagation-based (in-line) phase-contrast tomography are investigated; additionally, the effects of propagation distance, speckle mask material, number of speckle positions, and phase-retrieval algorithm on the quality of radiographic images and reconstructed tomography volumes are compared. The experimental setup, data acquisition settings, as well as phase retrieval and tomography reconstruction parameters are detailed, and concluding remarks are made regarding the strengths and weaknesses of each technique, their use case, and how the data acquisition parameters can be optimised for an extended field-of-view or in-situ imaging setup available at I12.
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Jan 2025
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I12-JEEP: Joint Engineering, Environmental and Processing
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Barbara
Bonechi
,
Margherita
Polacci
,
Fabio
Arzilli
,
Giuseppe
La Spina
,
Jean-Louis
Hazemann
,
Richard A.
Brooker
,
Robert
Atwood
,
Sebastian
Marussi
,
Peter D.
Lee
,
Roy A.
Wogelius
,
Jonathan
Fellowes
,
Mike R.
Burton
Diamond Proposal Number(s):
[28538]
Open Access
Abstract: Transitions in eruptive style during volcanic eruptions strongly depend on how easily gas and magma decouple during ascent. Stronger gas-melt coupling favors highly explosive eruptions, whereas weaker coupling promotes lava fountaining and lava flows. The mechanisms producing these transitions are still poorly understood because of a lack of direct observations of bubble dynamics under natural magmatic conditions. Here, we combine x-ray radiography with a novel high-pressure/high-temperature apparatus to observe and quantify in real-time bubble growth and coalescence in basaltic magmas from 100 megapascals to surface. For low-viscosity magmas, bubbles coalesce and recover a spherical shape within 3 seconds, implying that, for lava fountaining activity, gas and melt remain coupled during the ascent up to the last hundred meters of the conduit. For higher-viscosity magmas, recovery times become longer, promoting connected bubble pathways. This apparatus opens frontiers in unraveling magmatic/volcanic processes, leading to improved hazard assessment and risk mitigation.
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Aug 2024
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I11-High Resolution Powder Diffraction
I12-JEEP: Joint Engineering, Environmental and Processing
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Kay
Song
,
Guanze
He
,
Abdallah
Reza
,
Tamas
Ungar
,
Phani
Karamched
,
David
Yang
,
Ivan
Tolkachev
,
Kenichiro
Mizohata
,
Stephen P.
Thompson
,
Eamonn T.
Connolly
,
Robert C.
Atwood
,
Stefan
Michalik
,
David E. J.
Armstrong
,
Felix
Hofmann
Diamond Proposal Number(s):
[28444, 32094]
Open Access
Abstract: Severe plastic deformation changes the microstructure and properties of steels, which may be favourable for their use in structural components of nuclear reactors. In this study, high-pressure torsion (HPT) was used to refine the grain structure of Eurofer-97, a ferritic/martensitic steel. Electron microscopy and X-ray diffraction were used to characterise the microstructural changes. Following HPT at room temperature to a maximum shear strain of 230, the average grain size reduced by a factor of ~30, with a marked increase in high-angle grain boundaries. Dislocation density also increased by more than one order of magnitude. The thermal stability of the deformed material was investigated via in-situ annealing during synchrotron X-ray diffraction. This revealed substantial recovery between 450 K – 800 K. Irradiation with 20 MeV Fe-ions to ~0.1 dpa caused a 20% reduction in dislocation density compared to the as-deformed material. However, HPT deformation prior to irradiation only had a minor effect in mitigating the irradiation-induced reductions in thermal diffusivity and surface acoustic wave velocity of the material. Microstructural and material property changes are dominated by deformation compared to irradiation. In light of this, the benefits of using HPT to improve the irradiation resistance of Eurofer-97 are limited. These results provide a multi-faceted view of the changes in ferritic/martensitic steels due to severe plastic deformation, and how these changes can be used to alter material properties.
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Jul 2024
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I12-JEEP: Joint Engineering, Environmental and Processing
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Lorna
Sinclair
,
Oliver
Hatt
,
Samuel J.
Clark
,
Sebastian
Marussi
,
Elena
Ruckh
,
Robert C.
Atwood
,
Martyn
Jones
,
Gavin J.
Baxter
,
Chu Lun Alex
Leung
,
Iain
Todd
,
Peter D.
Lee
Diamond Proposal Number(s):
[20096]
Open Access
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Jul 2024
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Fabio
Arzilli
,
Margherita
Polacci
,
Giuseppe
La Spina
,
Nolwenn
Le Gall
,
Edward W.
Llewellin
,
Richard A.
Brooker
,
Rafael
Torres-Orozco
,
Danilo
Di Genova
,
David A.
Neave
,
Margaret E.
Hartley
,
Heidy M.
Mader
,
Daniele
Giordano
,
Robert
Atwood
,
Peter D.
Lee
,
Mike R.
Burton
Open Access
Abstract: The mobility and the rheological behaviour of magma within the Earth’s crust is controlled by magma viscosity. Crystallization and crystal morphology strongly affect viscosity, and thus mobility and eruptibility of magma, by locking it at depth or enabling its ascent towards the surface. However, the relationships between crystallinity, rheology and eruptibility remain uncertain because it is difficult to observe dynamic magma crystallization in real time.
Here we show the results of in situ 3D time-dependent, high temperature, moderate pressure experiments performed under water-saturated conditions to investigate crystallization kinetics in a basaltic magma. 4D crystallization experiments with in situ view were performed using synchrotron X-ray microtomography, which provides unique quantitative information on the growth kinetics and textural evolution of pyroxene crystallization in basaltic magmas. Crystallization kinetics obtained with 4D experiments were combined with a numerical model to investigate the impact of rapid dendritic crystallization on basaltic dike propagation, and demonstrate its dramatic effect on magma mobility and eruptibility.
We observe dendritic growth of pyroxene on initially euhedral cores, and a sur- prisingly rapid increase in crystal fraction and aspect ratio at undercooling ≥30 °C. Rapid dendritic crystallization favours a rheological transition from Newtonian to non-Newtonian behaviour within minutes. Modelling results show that dendritic crystallization at moderate undercooling (30-50 °C) can strongly affect magma rheology during magma ascent within a dike with important implications for the mobility of basaltic magmas within the crust. Our results provide insights into the processes that control whether magma ascent within the crust leads to eruption or not.
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Mar 2024
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[2370]
Open Access
Abstract: Surface roughness controls the mechanical performance and durability (e.g., wear and corrosion resistance) of laser powder bed fusion (LPBF) components. The evolution mechanisms of surface roughness during LPBF are not well understood due to a lack of in situ characterisation methods. Here, we quantified key processes and defect dynamics using synchrotron X-ray imaging and ex situ optical imaging and explained the evolution mechanisms of side-skin and top-skin roughness during multi-layer LPBF of Ti-6AI-4V (where down-skin roughness was out of the project scope). We found that the average surface roughness alone is not an accurate representation of surface topology of an LPBF component and that the surface topology is multimodal (e.g., containing both roughness and waviness) and multiscale (e.g., from 25 µm sintered powder features to 250 µm molten pool wavelength). Both roughness and topology are significantly affected by the formation of pre-layer humping, spatter, and rippling defects. We developed a surface topology matrix that accurately describes surface features by combining 8 different metrics: average roughness, root mean square roughness, maximum profile peak height, maximum profile valley height, mean height, mean width, skewness, and melt pool size ratio. This matrix provides a guide to determine the appropriate linear energy density to achieve the optimum surface finish of Ti-6AI-4V thin-wall builds. This work lays a foundation for surface texture control which is critical for build design, metrology, and performance in LPBF.
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Oct 2023
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I12-JEEP: Joint Engineering, Environmental and Processing
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Fan
Wu
,
Thomas
Flint
,
Renan M.
Kindermann
,
Matthew J.
Roy
,
Lu
Yang
,
Stuart
Robertson
,
Zhaoxia
Zhou
,
Michael
Smith
,
Pratheek
Shanthraj
,
Paul
English
,
Robert
Atwood
,
Wajira
Mirihanage
Diamond Proposal Number(s):
[24149]
Open Access
Abstract: The evolving interface forms between two different liquids during dissimilar welding can critically influence the development of the as-solidified microstructure and determine the mechanical properties of the joint. To investigate the interface evolution mechanisms during arc welding, time-resolved X-radiography was employed. The observations reveal the formation of transient finger-like protrusions at the dissimilar liquid interface prior to a brief, quasi-steady state. The analysis of the experimental observations using the magneto-thermal-hydrodynamic numerical simulations confirms that the quasi-steady state involves the formation of a short-lived solid phase, which alters the regular mixing during the process. Analysis of the in-situ experimental observations elucidate the interactions between thermal, momentum, electromagnetic and compositional fields which determine mechanisms of formation of the liquid interface instabilities and the melt pool shape. Based on the analysis, we extended our study to offer practical enhancement for dissimilar welding through offsetting the heat source.
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Aug 2023
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[28804]
Open Access
Abstract: Melt flow is critical to build quality during additive manufacturing (AM). When an external magnetic field is applied, it causes forces that alter the flow through the thermoelectric magnetohydrodynamic (TEMHD) effect, potentially altering the final microstructure. However, the extent of TEMHD forces and their underlying mechanisms, remain unclear. We trace the flow of tungsten particles using in situ high-speed synchrotron X-ray radiography and ex situ tomography to reveal the structure of TEMHD-induced flow during directed energy deposition AM (DED-AM). When no magnetic field is imposed, Marangoni convection dominates the flow, leading to a relatively even particle distribution. With a magnetic field parallel to the scan direction, TEMHD flow is induced, circulating in the cross-sectional plane, causing particle segregation to the bottom and side of the pool. Further, a downward magnetic field causes horizontal circulation, segregating particles to the other side. Our results demonstrate that TEMHD can disrupt melt pool flow during DED-AM.
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Jun 2023
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