I12-JEEP: Joint Engineering, Environmental and Processing
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Donal P.
Finegan
,
Julia
Billman
,
Jacob
Darst
,
Peter
Hughes
,
Jesus
Trillo
,
Matt
Sharp
,
Alex
Benson
,
Martin
Pham
,
Inez
Kesuma
,
Mark
Buckwell
,
Hamish T.
Reid
,
Charlie
Kirchner-Burles
,
Matilda
Fransson
,
David
Petrushenko
,
Thomas M. M.
Heenan
,
Rhodri
Jervis
,
Rhodri
Owen
,
Drasti
Patel
,
Ludovic
Broche
,
Alexander
Rack
,
Oxana
Magdysyuk
,
Matt
Keyser
,
William
Walker
,
Paul
Shearing
,
Eric
Darcy
Diamond Proposal Number(s):
[24112, 20903, 17641]
Open Access
Abstract: The thermal response of Li-ion cells can greatly vary for identical cell designs tested under identical conditions, the distribution of which is costly to fully characterize experimentally. The open-source Battery Failure Databank presented here contains robust, high-quality data from hundreds of abuse tests spanning numerous commercial cell designs and testing conditions. Data was gathered using a fractional thermal runaway calorimeter and contains the fractional breakdown of heat and mass that was ejected, as well as high-speed synchrotron radiography of the internal dynamic response of cells during thermal runaway. The distribution of thermal output, mass ejection, and internal response of commercial cells are compared for different abuse-test conditions, which when normalized on a per amp-hour basis show a strong positive correlation between heat output from cells, the fraction of mass ejected from the cells, their energy- and power-density. Ejected mass was shown to contain 10 × more heat per gram than non-ejected mass. The causes of ‘outlier’ thermal and ejection responses i.e., extreme cases, are elucidated by high-speed radiography which showed how occurrences such as vent clogging can create more hazardous conditions. High-speed radiography also demonstrated how the time-resolved interplay of thermal runaway propagation and mass ejection influences the total heat generated.
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Mar 2024
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I12-JEEP: Joint Engineering, Environmental and Processing
I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[22053, 30735, 31855]
Open Access
Abstract: Synchrotron X-ray imaging has been utilised to detect the dynamic behaviour of molten pools during the metal additive manufacturing (AM) process, where a substantial amount of imaging data is generated. Here, we develop an efficient and robust deep learning model, AM-SegNet, for segmenting and quantifying high-resolution X-ray images and prepare a large-scale database consisting of over 10,000 pixel-labelled images for model training and testing. AM-SegNet incorporates a lightweight convolution block and a customised attention mechanism, capable of performing semantic segmentation with high accuracy (∼96%) and processing speed (< 4 ms per frame). The segmentation results can be used for quantification and multi-modal correlation analysis of critical features (e.g. keyholes and pores). Additionally, the application of AM-SegNet to other advanced manufacturing processes is demonstrated. The proposed method will enable end-users in the manufacturing and imaging domains to accelerate data processing from collection to analytics, and provide insights into the processes’ governing physics.
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Mar 2024
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Kai
Zhang
,
Yunhui
Chen
,
Sebastian
Marussi
,
Xianqiang
Fan
,
Maureen
Fitzpatrick
,
Shishira
Bhagavath
,
Marta
Majkut
,
Bratislav
Lukic
,
Kudakwashe
Jakata
,
Alexander
Rack
,
Martyn A.
Jones
,
Junji
Shinjo
,
Chinnapat
Panwisawas
,
Chu Lun Alex
Leung
,
Peter D.
Lee
Open Access
Abstract: Porosity in directed energy deposition (DED) deteriorates mechanical performances of components, limiting safety-critical applications. However, how pores arise and evolve in DED remains unclear. Here, we reveal pore evolution mechanisms during DED using in situ X-ray imaging and multi-physics modelling. We quantify five mechanisms contributing to pore formation, migration, pushing, growth, removal and entrapment: (i) bubbles from gas atomised powder enter the melt pool, and then migrate circularly or laterally; (ii) small bubbles can escape from the pool surface, or coalesce into larger bubbles, or be entrapped by solidification fronts; (iii) larger coalesced bubbles can remain in the pool for long periods, pushed by the solid/liquid interface; (iv) Marangoni surface shear flow overcomes buoyancy, keeping larger bubbles from popping out; and (v) once large bubbles reach critical sizes they escape from the pool surface or are trapped in DED tracks. These mechanisms can guide the development of pore minimisation strategies.
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Feb 2024
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I13-2-Diamond Manchester Imaging
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Carles
Bosch
,
Joerg
Lindenau
,
Alexandra
Pacureanu
,
Christopher J.
Peddie
,
Marta
Majkut
,
Andrew C.
Douglas
,
Raffaella
Carzaniga
,
Alexander
Rack
,
Lucy
Collinson
,
Andreas T.
Schaefer
,
Heiko
Stegmann
Diamond Proposal Number(s):
[20274]
Open Access
Abstract: Correlative multimodal imaging is a useful approach to investigate complex structural relations in life sciences across multiple scales. For these experiments, sample preparation workflows that are compatible with multiple imaging techniques must be established. In one such implementation, a fluorescently labeled region of interest in a biological soft tissue sample can be imaged with light microscopy before staining the specimen with heavy metals, enabling follow-up higher resolution structural imaging at the targeted location, bringing context where it is required. Alternatively, or in addition to fluorescence imaging, other microscopy methods, such as synchrotron x-ray computed tomography with propagation-based phase contrast or serial blockface scanning electron microscopy, might also be applied. When combining imaging techniques across scales, it is common that a volumetric region of interest (ROI) needs to be carved from the total sample volume before high resolution imaging with a subsequent technique can be performed. In these situations, the overall success of the correlative workflow depends on the precise targeting of the ROI and the trimming of the sample down to a suitable dimension and geometry for downstream imaging. Here, we showcase the utility of a femtosecond laser (fs laser) device to prepare microscopic samples (1) of an optimized geometry for synchrotron x-ray tomography as well as (2) for volume electron microscopy applications and compatible with correlative multimodal imaging workflows that link both imaging modalities.
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Apr 2023
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I12-JEEP: Joint Engineering, Environmental and Processing
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William Q.
Walker
,
Kylie
Cooper
,
Peter
Hughes
,
Ian
Doemling
,
Mina
Akhnoukh
,
Sydney
Taylor
,
Jacob
Darst
,
Julia
Billman
,
Matthew
Sharp
,
David
Petrushenko
,
Rhodri
Owen
,
Martin
Pham
,
Thomas
Heenan
,
Alexander
Rack
,
Oxana
Magdysyuk
,
Thomas
Connolley
,
Dan
Brett
,
Paul
Shearing
,
Donal
Finegan
,
Eric
Darcy
Diamond Proposal Number(s):
[24112, 20903, 17641]
Abstract: Consideration of thermal runaway heat output variability is paramount for the development of safe lithium-ion battery assemblies. This study utilizes data gathered from fractional thermal runaway calorimetry (FTRC) experiments to conduct a comparative analysis of thermal runaway heat output for three cell formats (18650, 21700, and 33600) as a function of trigger method (heaters, internal short-circuiting device, and nail penetration). The analysis is based on comparisons for the calculated total energy yield, fractional energy yield, heat rate, and heat flux. This study reveals that nail penetration tends to result in higher thermal runaway heat output for larger cells (21700 & 33600); these experiments also tended to result in higher fractions of the total energy being released through the cell body. The smaller cells (18650) did not appear to have significant variation in heat output as a function of trigger method. This finding suggests that, for this cell type, worst-case scenario heat output could be achievable in assembly level testing regardless of the utilized trigger method. This study also demonstrates successful translation of FTRC results, as recorded in the Battery Failure Databank, into meaningful analysis that breaks down the influence of specific conditions on thermal runaway heat output.
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Mar 2022
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I12-JEEP: Joint Engineering, Environmental and Processing
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Matt
Sharp
,
John
Darst
,
Peter
Hughes
,
Julia
Billman
,
Martin
Pham
,
David
Petrushenko
,
Thomas
Heenan
,
Rhodri
Jervis
,
Rhodri Ellis
Owen
,
Drasti
Patel
,
Wenjia
Du
,
Harry
Michael
,
Alexander
Rack
,
Oxana
Magdysyuk
,
Thomas
Connolley
,
Dan
Brett
,
Gareth
Hinds
,
Matthew
Keyser
,
Eric
Darcy
,
Paul
Shearing
,
William Q.
Walker
,
Donal
Finegan
Diamond Proposal Number(s):
[24112, 20903, 17641]
Open Access
Abstract: Thermal runaway of lithium-ion batteries can involve various types of failure mechanisms each with their own unique characteristics. Using fractional thermal runaway calorimetry and high-speed radiography, the response of three different geometries of cylindrical cell (18650, 21700, and D-cell) to different abuse mechanisms (thermal, internal short circuiting, and nail penetration) are quantified and statistically examined. Correlations between the geometry of cells and their thermal behavior are identified, such as increasing heat output per amp-hour (kJ Ah-1) of cells with increasing cell diameter during nail penetration. High-speed radiography reveals that the rate of thermal runaway propagation within cells is generally highest for nail penetration where there is a relative increase in rate of propagation with increasing diameter, compared to thermal or internal short-circuiting abuse. For a given cell model tested under the same conditions, a distribution of heat output is observed with a trend of increasing heat output with increased mass ejection. Finally, internal temperature measurements using thermocouples embedded in the penetrating nail are shown to be unreliable thus demonstrating the need for care when using thermocouples where the temperature is rapidly changing. All data used in this manuscript are open access through the NREL and NASA Battery Failure Databank.
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Jan 2022
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I13-2-Diamond Manchester Imaging
Data acquisition
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Abstract: The virtual workshop on “X-ray Tomography at Synchrotron Facilities: Pipeline for Data Acquisition and Reduction” was held February 22–26, 2021, hosted by Elettra Sincrotrone Trieste (Italy) and organized through a joint collaboration between the Advanced Light Source (USA), the Advanced Photon Source (USA), the Diamond Light Source (UK), the European Synchrotron Radiation Facility (France), and Elettra Sincrotrone Trieste (Italy). The workshop was attended by 84 participants and animated by 22 speakers (see Figure 1). A total of 14 different synchrotron facilities were involved from Europe and the US as well as the SESAME synchotron Jordan (through the EC-funded project BEATS). In addition to the contributions from the organizer facilities, there was participation from SOLEIL (France), SSRL (USA), BESSY II (Germany), PETRA III (Germany), KARA (Germany), ALBA (Spain), MAX IV (Sweden), and the Swiss Light Source (Switzerland).
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Sep 2021
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Open Access
Abstract: To travel safely behind screens that can protect us from stones and hail, we must understand the response of glass to impact. However, without a means to observe the mechanisms that fail different silicate architectures, engineering has relied on external sensors, post-impact examination and best-guess to glaze our vehicles. We have used single and multi-bunch, X-ray imaging to differentiate distinct phases of failure in two silicates. We identified distinct micromechanisms, operating in tandem and leading to failure in borosilicate glass and Z-cut quartz. A surface zone in the amorphous glass densifies before bulk fracture occurs and then fails the block, whilst in quartz, fast cracks, driven down cleavage planes, fails the bulk. Varying the rate at which ejecta escapes by using different indenter tip geometries controls the failed target’s bulk strength. This opens the way to more physically based constitutive descriptions for the glasses allowing design of safer, composite panels by controlling the impulses felt by protective screens.
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Jun 2020
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Yuliang
Zhao
,
Weiwen
Zhang
,
Billy
Koe
,
Wenjia
Du
,
Mengmeng
Wang
,
Weilin
Wang
,
Elodie
Boller
,
Alexander
Rack
,
Zhenzhong
Sun
,
Da
Shu
,
Baode
Sun
,
Jiawei
Mi
Abstract: Scandium (Sc) has been long recognized as one of the most effective grain refining elements for Al alloys because of the Al3Sc phases formed in an Al melt containing Sc. However, there are still lack of comprehensive studies on the exact mechanism of how Al3Sc phases are nucleated in Al melt and their true 3D structures. In this paper, we used scanning/transmission electron microscopy and synchrotron X-ray tomography to study the nucleation and true 3D structure of primary Al3Sc phases in an Al-2wt%Sc alloy. The multiscale characterization approach revealed that the micrometre α-Al2O3 particles present in the Al melt can facilitate the formation of stacking faults at the α-Al2O3/Al3Sc interface and therefore promote heterogenous nucleation of Al3Sc phases. SEM and tomography clearly revealed that individual primary Al3Sc phases were simple cubes with the edge length of 10–35 μm; and majority of them were interconnected to form clusters with the peak value of 10,000 μm3. At the interface between an Al matrix and an Al3Sc cube, the Al3Sc phases can also grow into nanometre size particle clusters due to the depletion of Sc.
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Apr 2020
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Yingyue
Xu
,
Nan
Xia
,
Michelle
Lim
,
Xiaodong
Tan
,
Minh Ha
Tran
,
Erin
Boulger
,
Fei
Peng
,
Hunter
Young
,
Christoph
Rau
,
Alexander
Rack
,
Claus-Peter
Richter
Open Access
Abstract: An emerging method in the field of neural stimulation is the use of photons to activate neurons. The possible advantage of optical stimulation over electrical is attributable to its spatially selective activation of small neuron populations, which is promising in generating superior spatial resolution in neural interfaces. Two principal methods are explored for cochlear prostheses: direct stimulation of nerves with infrared light and optogenetics. This paper discusses basic requirements for developing a light delivery system (LDS) for the cochlea and provides examples for building such devices. The proposed device relies on small optical sources, which are assembled in an array to be inserted into the cochlea. The mechanical properties, the biocompatibility, and the efficacy of optrodes have been tested in animal models. The force required to insert optrodes into a model of the human scala tympani was comparable to insertion forces obtained for contemporary cochlear implant electrodes. Side-emitting diodes are powerful enough to evoke auditory responses in guinea pigs. Chronic implantation of the LDS did not elevate auditory brainstem responses over 26 weeks.
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Oct 2018
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