DIAD-Dual Imaging and Diffraction Beamline
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Christina
Reinhard
,
Michael
Drakopoulos
,
Sharif I.
Ahmed
,
Hans
Deyhle
,
Andrew
James
,
Christopher M.
Charlesworth
,
Martin
Burt
,
John
Sutter
,
Steven
Alexander
,
Peter
Garland
,
Thomas
Yates
,
Russell
Marshall
,
Ben
Kemp
,
Edmund
Warrick
,
Armando
Pueyos
,
Ben
Bradnick
,
Maurizio
Nagni
,
A. Douglas
Winter
,
Jacob
Filik
,
Mark
Basham
,
Nicola
Wadeson
,
Oliver N. F.
King
,
Navid
Aslani
,
Andrew J.
Dent
Open Access
Abstract: The Dual Imaging and Diffraction (DIAD) beamline at Diamond Light Source is a new dual-beam instrument for full-field imaging/tomography and powder diffraction. This instrument provides the user community with the capability to dynamically image 2D and 3D complex structures and perform phase identification and/or strain mapping using micro-diffraction. The aim is to enable in situ and in operando experiments that require spatially correlated results from both techniques, by providing measurements from the same specimen location quasi-simultaneously. Using an unusual optical layout, DIAD has two independent beams originating from one source that operate in the medium energy range (7–38 keV) and are combined at one sample position. Here, either radiography or tomography can be performed using monochromatic or pink beam, with a 1.4 mm × 1.2 mm field of view and a feature resolution of 1.2 µm. Micro-diffraction is possible with a variable beam size between 13 µm × 4 µm and 50 µm × 50 µm. One key functionality of the beamline is image-guided diffraction, a setup in which the micro-diffraction beam can be scanned over the complete area of the imaging field-of-view. This moving beam setup enables the collection of location-specific information about the phase composition and/or strains at any given position within the image/tomography field of view. The dual beam design allows fast switching between imaging and diffraction mode without the need of complicated and time-consuming mode switches. Real-time selection of areas of interest for diffraction measurements as well as the simultaneous collection of both imaging and diffraction data of (irreversible) in situ and in operando experiments are possible.
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Nov 2021
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[18836]
Abstract: In this study we investigated the evolution of meso-scale internal stresses and those effects on local deformation behaviour during incremental plastic and creep deformation in type 316H stainless steel at 550°C, using in-situ X-ray synchrotron diffraction and crystal plasticity modelling. Owing to the fast data accusation rate of synchrotron diffraction technique, for the first time, the transient behaviour of different grain families was captured during initial fast stress relaxation period of the displacement-controlled creep dwells. Significantly it is found that the evolution of internal stresses during time independent plastic deformation is distinct from that during time dependent creep deformation. During plastic deformation, lattice strains in the {311} grain family exhibit linear behaviour whereas during creep deformation it exhibits non-linear behaviour, instead the {111} grain family exhibit linear behaviour. A novel unified constitutive law was devised within crystal plasticity framework based on the theoretical physics; the model successfully predicts the macroscopic deformation behaviour as well as the distinction between the evolution of meso-scale internal stresses during plastic and creep deformation, therefore, correctly accounting for the effect of internal stresses generated during plastic deformation on the subsequent creep deformation. The validated model has elucidated the grain-neighbouring effects on individual grain deformations.
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Jun 2021
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I12-JEEP: Joint Engineering, Environmental and Processing
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C.
Paraskevoulakos
,
J. P.
Forna-Kreutzer
,
K. R.
Hallam
,
C. P.
Jones
,
T. B.
Scott
,
C.
Gausse
,
D. J.
Bailey
,
C. A.
Simpson
,
D.
Liu
,
C.
Reinhard
,
C. L.
Corkhill
,
M.
Mostafavi
Diamond Proposal Number(s):
[20189]
Open Access
Abstract: Decommissioning of the damaged Chernobyl nuclear reactor Unit 4 is a top priority for the global community. Before such operations begin, it is crucial to understand the behaviour of the hazardous materials formed during the accident. Since those materials formed under extreme and mostly unquantified conditions, modelling alone is insufficient to accurately predict their physical, chemical and, predominantly, mechanical behaviour. Meanwhile, knowledge of the mechanical characteristics of those materials, such as their strength, is a priority before robotic systems are employed for retrieval and the force expected from them to be exerted is one of the key design questions. In this paper we target to measurement of the standard mechanical properties of the materials formed during the accident by testing small-scale, low radioactivity simulants. A combined methodology using Hertzian indentation, synchrotron X-ray tomography and digital volume correlation (DVC), was adopted to estimate the mechanical properties. Displacement fields around the Hertzian indentation, performed in-situ in a synchrotron, were measured by analysing tomograms with DVC. The load applied during the indentation, combined with full-field displacement measured by DVC was used to estimate the mechanical properties, such as Young's modulus and Poisson's ratio of these hazardous materials.
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Mar 2021
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[16096]
Abstract: Thermal shocks are an important incident in operation of a pressure vessel which can have a significant impact on the structural integrity of the vessel. Often experiments that consider the state of the vessel before and after the thermal shock are used to evaluate the effects of the thermal shock. The studies can be complemented by time-resolved numerical simulations, which may be validated against the final state of the vessel obtained experimentally, to infer the transient response of the material. The transient response is important as the material experiences the highest level of stress in a short period which can induce catastrophic failure. This paper reports time-resolved experimental quantification of strain in reactor pressure vessel material during thermal shock measured by in-situ synchrotron diffraction. Specimens were extracted from a plate of nuclear pressure vessel steel with a nickel alloy cladding deposited by overlay welding. The specimens, with and without cracks, were subjected to thermal loading by heating then rapidly quenching the cladding in cold water. Strains were measured during thermal loading at a point near the crack tip from which the stress state around the crack tip was calculated and compared with a transient finite element model of the experiment. It was found that the peak near-tip stress occurred within the first second after the onset of rapid cooling. It was demonstrated from experimental measurements that the peak stress intensity factor occurred during thermal shock, rather than under steady conditions before or after the thermal shock. It was shown that although the finite element simulation predicts the steady state condition of the material after thermal shock, its transient response dependents significantly on a number of inputs with high uncertainty, making its time-resolved results unreliable for high-fidelity integrity assessments.
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Oct 2020
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[12606]
Abstract: Effects of plastic constraint on the fracture of materials have been studied extensively. Often in such studies, the plastic constraint is divided into in-plane and out-of-plane directions and each treated separately. Such a separation adds considerable complexity to the engineering structural integrity assessment analyses. Despite previous suggestions for unifying the effects of constraint in a single parameter, the current engineering assessments have not been updated due to lack of direct experimental validation of such parameters. In this study, we directly measured the effects of in-plane and out-of-plane constraints, for the first time, in the form of plastic zone around the crack using advanced experimental techniques. The measurement of constraints in four specimens with different levels of in and out of plane constraints, allowed us to show and relate the interdependency of in and out of plane constraints. The tests were carried out using synchrotron X-ray tomography with in-situ loading. Attenuation contrast between the constituents of the metal matrix composite material used allowed the tomograms to be analysed using digital volume correlation which calculated the full-field displacement within the samples. The displacement fields were used via a finite element framework to calculate the energy release rate in the form of the J-integral along the crack fronts. The measured plastic zone sizes, dependant on the combined level of in plane and out of plane constraints, were used successfully to rank the J-Integral at fracture of the samples. It was therefore proved the level of plastic constraint can be quantified by using the size of the plastic zone as without separating it into two components thus simplifying the treatment of constraint in structural analyses significantly.
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Aug 2020
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[18836]
Abstract: The creep life and deformation behaviour of high-temperature steels can be significantly affected by the prior plastic loading. This effect is partly due to the generation of intergranular strains from the grain-scale elastic and plastic anisotropic deformation during plastic loading. This paper investigates the effect of these plasticity generated intergranular strains on the subsequent creep strain accumulation behavior in type 316H stainless steel. An in-situ synchrotron diffraction experiment was conducted at 550°C, where the sample was loaded incrementally to different magnitudes of plastic strain, followed by a displacement-controlled stress relaxation dwell at each of this stage. The lattice strains of 4 grain families were measured during these stages. It was found that the intergranular strains generated during the plastic deformation significantly affect the relative magnitude of creep strain accumulation in different grain families. A subtle but significant difference has been observed between the creep intergranular strain accumulation behavior and the plastic intergranular strain accumulation behavior in different grain families which can be used to interrogate the validity of any micromechanical models’ formulation for creep and plastic deformation. The macroscopic stress relaxations measured from the experiment were compared with the prediction from a novel crystal plasticity based micromechanical model developed in our group. A good overall match was found between the experiment and the model regarding the magnitude of stress relaxation after various level of plasticity. The experiments have demonstrated that the model requires further development to accurately predict the rate of stress relaxation and the micro scale lattice strain evolution during creep.
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Nov 2019
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Data acquisition
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A. D.
Parsons
,
S.
Ahmed
,
M.
Basham
,
D.
Bond
,
B.
Bradnick
,
M.
Burt
,
T.
Cobb
,
N.
Dougan
,
M.
Drakopoulos
,
F.
Ferner
,
J.
Filik
,
C.
Forrester
,
L.
Hudson
,
P.
Joyce
,
B.
Kaulich
,
A.
Kavva
,
J.
Kelly
,
J.
Mudd
,
B.
Nutter
,
P.
Quinn
,
K.
Ralphs
,
C.
Reinhard
,
J.
Shannon
,
M.
Taylor
,
T.
Trafford
,
X.
Tran
,
E.
Warrick
,
A.
Wilson
,
A. D.
Winter
Open Access
Abstract: We present a beamline analogue, capable of system pro- totyping, integrated development and testing, specifically designed to provide a facility for full scientific testing of instrument prototypes. With an identical backend to real beamline instruments the P99 development rig has allowed increased confidence and troubleshooting ahead of final scientific commissioning. We present detail of the software and hardware components of this environment and how these have been used to develop functionality for the new operational instruments. We present several high impact examples of such integrated prototyping development in- cluding the instrumentation for DIAD (integrated Dual Im- aging And Diffraction) and the J08 (Soft X-ray ptychogra- phy) beamline end station.
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Oct 2019
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B18-Core EXAFS
I11-High Resolution Powder Diffraction
I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[16863, 16328]
Abstract: A combination of X-ray analytical techniques has been used to study the microstructure and corrosion of a 450-year-old cast-iron cannonball fragment from the Mary Rose shipwreck. Using a 3D approach, it has been shown that akaganeite, β-FeO(OH, Cl), starts to appear ˜1.5 mm below the outer surface of the object, occurring selectively around non-contiguous graphite flakes in the microstructure, with no corrosion in graphite-free regions. This spatial analysis has given a new look inside a 450-year-old system, to see how metallographic features interact with local chemical environments to give complex corrosion products, centuries in the making.
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Aug 2019
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[12606]
Abstract: In-situ fracture tests were carried out on the I12 beamline at the Diamond Light Source. Four Al-Ti metal-matrix composites (MMCs), with two crack lengths, were studied to assess for the impact of in-plane constraint. Synchrotron X-ray computed tomography and synchrotron X-ray diffraction were used to measure total strain and elastic strain respectively. In this work, the measured elastic strains in the samples are detailed as a function of applied load and compared against those predicted from a 3D elastic-plastic finite element model. The modelled strains increased asymptotically towards the tip of the electro discharge machined notch. The experimental results do not highlight the same response, which is due to a combination of blunting and low experimental spatial resolution. Far field experimental and measured strain fields converged, notably in the test piece containing a long notch (
a/W
= 0.5) and higher levels of constraint.
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Jun 2019
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I12-JEEP: Joint Engineering, Environmental and Processing
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Liya
Guo
,
Na
Mi
,
Haval
Mohammed-Ali
,
Majid
Ghahari
,
Andrew
Du Plessis
,
Angus
Cook
,
Steven
Street
,
Christina
Reinhard
,
Robert C.
Atwood
,
Trevor
Rayment
,
Alison J.
Davenport
Diamond Proposal Number(s):
[7412]
Open Access
Abstract: Atmospheric corrosion of stainless steel can take place when airborne salt particles deposit on the metal surface, forming droplets when the relative humidity (RH) reaches a critical value: the deliquescence relative humidity of the salt. Most work to date has focused on single salts such as MgCl2 or NaCl. In the present work, the effect of mixed salts is investigated at 45% RH, above the deliquescence relative humidity of MgCl2 but below that of NaCl. Dish-shaped pits were found in pure MgCl2 solutions and mixed solutions. Crevice corrosion takes place under NaCl crystals. This is shown both with ex situ measurements and in situ time-dependent measurements using X-ray microtomography, where pit growth was also monitored.
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Jan 2019
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