@article{J\"{a}nicke2022,

title = {Debonding analysis via digital volume correlation during in-situ pull-out tests on fractal fibers},

author = {G. J\"{a}nicke and A. Vintache and B. Smaniotto and A. Fau and I. Farina and F. Fraternali and F. Hild},

doi = {10.1016/j.jcomc.2022.100302},

year  = {2022},

date = {2022-08-23},

journal = {Composites Part C},

volume = {9},

issue = {100302},

abstract = {The quantification of debonding was performed for additively manufactured “fractal” fibers embedded within two brittle matrices. Three pull-out tests were carried out inside of an X-ray tomograph allowing for Digital Volume Correlation analyses. Relative motions at the interfaces were measured thanks to adapted meshes with split nodes. Profiles of normal, tangential and vertical displacement jumps as well as vertical strains in the fibers were used to study interfacial debonding. An articulated load transfer mechanism between the fiber and the matrix was observed in the examined tests, as demonstrated by zigzagged distributions of vertical displacement jumps and vertical strain profiles in the fibers at the initial stages of pull-out. Vertical strain concentrations were observed in correspondence to lateral protrusions (or ribs) of the reinforcing fibers. These results suggest that fiber\textendashmatrix interlocking may be affected by geometry-driven tensile stiffening effects between the ribs. For larger values of pull-out displacements, more diffuse damage of the fiber\textendashmatrix interface was observed between the ribs, especially in plaster matrices.},

keywords = {Tomographe},

pubstate = {published},

tppubtype = {article}

}

@article{Gaudez2022,

title = {3D deep convolutional neural network segmentation model for precipitate and porosity identification in synchrotron X-ray tomograms},

author = {Steve Gaudez and Meriem Ben Haj Slama and Anders Kaestner and Manas Vijay Upadhyay},

editor = {A. Bergamaschi, Paul Scherrer Institut, Switzerland},

url = {https://journals.iucr.org/s/issues/2022/05/00/gy5036/gy5036.pdf},

doi = {10.1107/S1600577522006816 },

issn = {1600-5775},

year  = {2022},

date = {2022-07-04},

journal = {Journal of Synchrotron Radiation},

volume = {29},

pages = {1232\textendash1240},

keywords = {Helios, Titan},

pubstate = {published},

tppubtype = {article}

}

@article{Auger2021,

title = {Crack Path and Liquid Metal Embrittlement Specificity of Austenitic Steels in Mercury at Room Temperature},

author = {Thierry Auger and Bassem Barkia and Eva H\'{e}ripr\'{e} and Vincent Michel and Denis Mutel and Ivan Guillot and Zehoua Hamouche and Liliana Medina-Almazan},

url = {https://papers.ssrn.com/sol3/Delivery.cfm/09131282-2c86-46df-9fe5-3a2622f23d2f-MECA.pdf?abstractid=3953177\&mirid=1\&type=2},

year  = {2022},

date = {2022-07-01},

urldate = {2021-10-30},

journal = {Scripta Materialia},

volume = {215},

number = {114733},

abstract = {A liquid metal embrittlement specificity of three austenitic steels with increasing nickel content (304 L, 316 L and 316L(N)) is studied in liquid mercury in the axisymmetric notched geometry. Only the low nickel alloys are susceptible to LME. The crack path of an austenitic steel fracture induced by liquid mercury has been elucidated at microstructural scale. Deformation induced martensite (γ(fcc) → α’(bcc)) of the low nickel steels induces numerous α’/α’ interfaces at small scale that are susceptible to be embrittled. Because the only steel that resists LME is the one that shows stability over α’ phase change due mostly to its higher nickel content, a point confirmed by X Ray fractography, it is inferred that the major factor contributing to the LME sensitivity at room temperature is the α’ phase formation in unstable austenitic steels during plastic strain. This provides a sound rationale on how to prevent mercury induced embrittlement with austenitic steels.},

keywords = {Helios},

pubstate = {published},

tppubtype = {article}

}

@article{Vargas2022,

title = {Cohesive properties of refractory castable at 600°C: Effect of sintering and testing temperature},

author = {Raphael Vargas and R B Canto and Fran\c{c}ois Hild},

editor = {Elsevier},

url = {https://hal.archives-ouvertes.fr/hal-03705439/file/JECS2022-ccsd.pdf},

doi = {10.1016/j.jeurceramsoc.2022.06.070￿},

year  = {2022},

date = {2022-06-29},

urldate = {2022-06-29},

journal = {Journal of the European Ceramic Society},

volume = {42},

issue = {14},

pages = {6733-6749},

abstract = {This paper aims to evaluate cohesive properties for an alumina refractory with mullite-zirconia aggregates from wedge splitting tests (WST), and to assess their sensitivity to sintering and testing temperature. Five experiments were analyzed of which four were performed at 600°C. The sought parameters were determined via weighted finite element model updating. The cohesive strength and the fracture energy were successfully calibrated and resulted in simulated data close to their experimental counterparts (i.e., between 4 and 11 times the measurement uncertainty). Increasing the sintering temperature from 1400°C to 1450°C enhanced the cohesion between the mullite-zirconia aggregates and the alumina matrix (20% increase of the fracture energy and of the fracture process zone length). When the WSTs were performed at 600°C, the cohesive strength was 10% smaller while the fracture energy was 70% higher than that at room temperature.},

keywords = {Tomographe},

pubstate = {published},

tppubtype = {article}

}

@article{Valmalle2022b,

title = {Local-global DVC analyses confirm theoretical predictions for deformation and damage onset in torsion of pantographic metamaterial},

author = {Malo Valmalle and Antoine Vintache and Benjamin Smaniotto and F. Gutmann and M. Spagnuolo and A. Ciallella and Fran\c{c}ois Hild},

editor = {Elsevier},

url = {https://hal.archives-ouvertes.fr/hal-03706227/file/MOM2022-ccsd.pdf},

doi = {10.1016/j.mechmat.2022.104379￿},

year  = {2022},

date = {2022-06-27},

urldate = {2022-06-27},

journal = {Mechanics of Materials},

volume = {172},

pages = {104379},

abstract = {Pantographs are a special class of metamaterials that do not obey theories of first gradient continua. In the present work, a pantographic metamaterial was printed and subjected to in situ torsion. The experiment was designed in order to investigate damage onset modalities in large torsional deformations of pantographic mesostructures. To account for the presence of true pivots, multiple point constraints were implemented in the DVC procedure. Local-global DVC was validated thanks to a series of steps accounting for numerous pivots. It was possible to determine the dominant damage mechanism in torsion. Damage was detected thanks to the strain and residual fields. Moreover, important modeling indications were obtained to guide further theoretical and experimental investigations.},

keywords = {Tomographe},

pubstate = {published},

tppubtype = {article}

}

@article{Chiche2022,

title = {Inspecting CAD/CAM ceramic dental prosthesis using X-ray micro-computed tomography},

author = {Norman Chiche and William Pacquet and Nicolas Lebon and Elsa Vennat and Laurent Tapie},

doi = {10.1080/21681163.2022.2092033},

year  = {2022},

date = {2022-06-26},

journal = {Computer Methods in Biomechanics and Biomedical Engineering: Imaging \& Visualization},

abstract = {The X-ray micro-computed tomography measurement protocol proposed in this paper aims to inspect the geometrical quality of ceramic dental prostheses manufactured by dental CAD/CAM systems. This measurement protocol sits at the interface of dental CAD/CAM technology and dental CAD/CAM engineering, which will interest to the dentistry community. The main objective of this paper is to provide a turnkey solution to researchers with a medical-education background for 3D inspection of dental prostheses. The proposed protocol hinges on 3D digitisation, obtained by X-ray micro-computed tomography acquisition and image processing. Before using it in a realistic case, the protocol has been validated by inspecting a certified ceramic sphere. The measurements demonstrated errors under the level of clinical tolerance. A realistic prosthesis was then designed and machined. Our protocol revealed under-milled areas, over-milled areas, and, particularly, chipping on thinnest areas. This protocol is crucial for overcoming the inherent difficulties in exchanging information between dentistry practice and dental CAD/CAM systems development.},

keywords = {Tomographe},

pubstate = {published},

tppubtype = {article}

}

@article{Shariati2022,

title = {Probing Constitutive Models of Bohus Granite with In Situ Spherical Indentation and Digital Volume Correlation},

author = {H Shariati and Amine Bouterf and M Saadati and P.-L Larsson and Fran\c{c}ois Hild},

editor = {Springer Verlag},

url = {https://hal.archives-ouvertes.fr/hal-03705005/document},

doi = {0.1007/s00603-022-02991-9},

year  = {2022},

date = {2022-06-26},

journal = {Rock Mechanics and Rock Engineering},

abstract = {Spherical indentation of granite was investigated using Digital Volume Correlation (DVC) aiming at probing constitutive laws of the studied rock. In situ indentation was performed within an X-ray tomograph. Finite element simulations of the problem, using different constitutive models, were carried out and their trustworthiness was assessed thanks to DVC residuals. Three laws were investigated, namely, pure elasticity, then compressible elastoplasticity, and finally compressible

elastoplasticity coupled with damage. Frictional contact effects were studied as well. The results show that compressible elastoplasticity should be accounted for to achieve high accuracy of results, and that frictional effects are of importance in terms of damage extent. If macrocrack initiation is also sought, then damage features should be included in the model.},

keywords = {Tomographe},

pubstate = {published},

tppubtype = {article}

}

@article{Neggers2022,

title = {A generic topography reconstruction method based onmulti-detector backscattered electron images},

author = {Jan Neggers and Eva H\'{e}ripr\'{e} and Marc Bonnet and Simon Hallais and St\'{e}phane Roux},

doi = {10.1111/str.12416},

year  = {2022},

date = {2022-05-29},

journal = {Strain},

abstract = {Surface topographies can be reconstructed from backscattered electron (BSE) images captured from different detector orientations. This article presents a very general approach to this problem, in the spirit of photometric stereo methods, allowing for arbitrary BSE detector number (at least 3) and shapes. The general idea is to both determine the (non-linear) model parameters and compute the surface topography so that the modelled images match at best the acquired ones. Three samples are used for validation of the measured topography with respect to atomic force microscopy (AFM) measurements. Root mean square (RMS) errors in the range of 10\textendash35 nm, or 1\textendash1.5% of total sampleheight, are obtained.},

keywords = {Helios},

pubstate = {published},

tppubtype = {article}

}

@article{Valmalle2022,

title = {Digital Volume Correlation analyses to study deformation and damage mechanisms of teak in torsion},

author = {Malo Valmalle and Montcho Cr\'{e}pin Hounlonon and Benjamin Smaniotto and Cl\'{e}ment A. Kouchad\'{e} and Fran\c{c}ois Hild},

doi = {10.5802/crmeca.107},

year  = {2022},

date = {2022-04-07},

journal = {Comptes Rendus. M\'{e}canique},

volume = {350},

pages = {85-98},

abstract = {Wood is a material with anisotropic elastic properties at the macroscale. In the present work, a sample made of Beninise teak was subjected to in situ torsion. Digital Volume Correlation (DVC) analyses

were run at the mesoscale to measure displacement fields. The corresponding strain fields were obtained at the same scale in addition to the gray level residuals at the voxel scale. The out-of-plane shear modulus could be calibrated at the macroscale and was in good agreement with earlier results of the coauthors (MCH and CAK). The ultimate shear strength was also assessed at the same scale. Last, damage was detected and quantified at the mesoscale thanks to strain fields and at the microscale via gray level residual fields.},

keywords = {Tomographe},

pubstate = {published},

tppubtype = {article}

}

@article{Cavillon2022,

title = { Thermal and Electron Plasma Effects on Phase Separation Dynamics Induced by Ultrashort Laser Pulses},

author = {Maxime Cavillon and Jing Cao and Maxime Vallet and Fran\c{c}ois Brisset and L\'{e}o Mazerolles and Brahim Dkhil and Matthieu Lancry and Bertrand Poumellec},

url = {https://www.mdpi.com/2073-4352/12/4/496/htm},

doi = {10.3390/cryst12040496},

year  = {2022},

date = {2022-04-03},

journal = {Crystals},

volume = {12},

issue = {4},

pages = {496},

abstract = {During ultrafast laser-induced crystallization from glass with a non-congruent composition, a phase separation occurs. The morphology of the crystallized area, inside the heat-affected zone (HAZ), is spectacular showing a bouquet-like structure, under some specific conditions related to glass chemical composition and laser parameters. In this work, we investigate this HAZ along a written line through a set of high-resolution electron microscopy techniques to probe both the morphology and the chemical distribution at the nanoscale. Based on these findings, we demonstrate that the bouquet-like structure arises from poorly textured nanocrystals between two regions that have probably accumulated elastic strain. From that analysis, we also provide insights into the chemical separation process during this complex light-matter transformation in which the induced plasma structure guides the spatial distribution of SiO2 and LiNbO3. We suggest a model based on an electric field modulation produced by the inhomogeneous plasma electron trapping, that modifies the electrochemical potentials of the constituents. },

keywords = {Titan},

pubstate = {published},

tppubtype = {article}

}

@article{Dionnet2022,

title = {Multiscale correlated analysis of the Aguas Zarcas CM chondrite},

author = {Z\'{e}lia Dionnet and Alice Al\'{e}on-Toppani and Rosario Brunetto and Stefano Rubino and Martin D. Suttle and Cateline Lantz and Chrysa Avdellidou and Donia Baklouti and Ferenc Borondics and Zahia Djouadi and Francesco Greco and Eva H\'{e}ripr\'{e} and Tomoki Nakamura and Alessandra Rotundi and Mario Scheel},

doi = {10.1111/maps.13807},

year  = {2022},

date = {2022-03-23},

journal = {Meteoritics \& Planetary Science},

abstract = {In this paper, we report the results of a campaign of measurements on four fragments of the CM Aguas Zarcas (AZ) meteorite, combining X-ray computed tomography analysis and Fourier-transform infrared (FT-IR) spectroscopy. We estimated a petrologic type for our sampled CM lithology using the two independent techniques, and obtained a type CM2.5, in agreement with previous estimations. By comparing the Si-O 10-µm signature of the AZ average FT-IR spectra with other well-studied CMs, we place AZ in the context of aqueous alteration of CM parent bodies. Morphological characterization reveals that AZ has heterogeneous distribution of pores and a global porosity of 4.5 ± 0.5 vol%. We show that chondrules have a porosity of 6.3 ± 1 vol%. This larger porosity could be inherited due to various processes such as temperature variation during the chondrule formation and shocks or dissolution during aqueous alteration. Finally, we observed a correlation between 3D distributions of organic matter and mineral at micrometric scales, revealing a link between the abundance of organic matter and the presence of hydrated minerals. This supports the idea that aqueous alteration in AZ’s parent body played a major role in the evolution of the organic matter.},

keywords = {Helios},

pubstate = {published},

tppubtype = {article}

}

@article{Silva2022,

title = {Colloidal Synthesis of Nanoparticles: from Bimetallic to High Entropy Alloys},

author = {Cora Moreira Da Silva and Hakim Amara and Fr\'{e}d\'{e}ric Fossard and Armelle Girard and Annick Loiseau and Vincent Huc},

url = { https://hal.archives-ouvertes.fr/hal-03597703},

doi = {arxiv-2203.03945},

year  = {2022},

date = {2022-03-08},

journal = {arXiv.cond-mat.mtrl-sci},

abstract = {At the nanometric scale, the synthesis of a random alloy (i.e. without phase segregation, whatever the composition) by chemical synthesis remains a not easy task, even for simple binary type systems. In this context, a unique approach based on the colloidal route is proposed enabling the synthesis of face-centred cubic and monodisperse bimetallic, trimetallic, tetrametallic and pentametallic nanoparticles with diameters around 5 nm as solid solutions. The Fe-Co-Ni-Pt-Ru alloy and its subsets are considered which is a challenging task as each element has fairly different physico-chemical properties. Nanoparticles are prepared by temperature-assisted co-reduction of metal acetylacetonate precursors in the presence of surfactants. It is highlighted how the correlation between precursors' degradation temperatures and reduction potentials values of the metal cations is the driving force to achieve a homogenous distribution of all elements within the nanoparticles.},

keywords = {Titan},

pubstate = {published},

tppubtype = {article}

}

@article{Rambausek2022,

title = {A computational framework for magnetically hard and soft viscoelastic magnetorheological elastomers},

author = {Matthias Rambausek and Dipayan Mukherjee and Kostas Danas},

editor = {Elsevier B.V.},

url = {https://doi.org/10.1016/j.cma.2021.114500},

doi = {10.1016/j.cma.2021.114500},

issn = {00457825},

year  = {2022},

date = {2022-03-01},

urldate = {2022-03-01},

journal = {Computer Methods in Applied Mechanics and Engineering},

volume = {391},

number = {114500},

abstract = {This work deals with a comprehensive theoretical and numerical framework that allows the modeling of finite strain magnetorheological elastomers (MREs) comprising mechanically soft nonlinear elastic\textendashviscoelastic polymer phases and magnetically hard (i.e. dissipative) or soft (i.e. purely energetic) magnetic phases. The framework is presented in a general manner and is implemented using the finite element method. Two software implementations are developed, one using FEniCS and the other in Abaqus. A detailed analysis of the numerical schemes used to model the surrounding air is made and their pros and cons are discussed. The proposed framework is used to simulate two model geometries that are directly relevant to recent applications of MREs. The first two-dimensional example simulates a mechanically soft beam consisting of a single wavy-chain of hard or soft magnetic particles. The beam is subjected to transverse magnetic actuation loads that induce important vertical deflections. Despite the overall small local strains in the beam, a significant viscoelastic effect is observed when high-rate magnetic fields are applied. A torque model for the particles is also used to analyze the beam geometry and is found to be in relatively good agreement with the rest of the approaches for small actuation fields. The second example discusses the rotation of a three-dimensional ellipsoid embedded in a cubic elastomer domain, while the ensemble lies inside a larger cubic air domain. Non-monotonic uniaxial and rotating magnetic fields are applied leading to complex, non-monotonic rotations of the ellipsoidal particle. The hard and soft magnetic cases exhibit significant differences, whereas viscoelasticity is found to induce strong coupling with the magnetization rotation but not with the dissipative magnetization amplitude. Extensive supplementary material provides all details of our implementations as well as animated visualization of results.},

keywords = {Cluster},

pubstate = {published},

tppubtype = {article}

}

@article{dePastre2022,

title = {Shape defect analysis from volumetric data - Application to lattice struts in additive manufacturing},

author = {Marc-Antoine de Pastre and Yann Quinsat and Claire Lartigue},

doi = {10.1016/j.precisioneng.2022.02.011},

year  = {2022},

date = {2022-02-26},

journal = {Precision Engineering},

volume = {76},

pages = {12-28},

abstract = {Additive manufacturing (AM) revolutionises the way parts are produced as it offers a variety of design freedom. Lattice structures are an illustration of this AM freedom, allowing for the production of complex geometries that are being investigated in many applications. However, lattice structures present different typology of defects such as surface quality, porosity or dimensional inaccuracies. The most adapted measurement technology to reveal AM internal defects falls into X-ray computed tomography (XCT). Although there have been significant efforts in modelling lattice structure defects from XCT, a direct and accurate link between volumetric data of the part being measured and the CAD model is still required. This direct link would have the noteworthy advantage of not involving XCT surface determination tool, which choice may be discussed. In this paper, shape defects from metal laser powder bed fusion (PBF) strut-based lattice structures are studied. Different struts are printed as representative of BCCz lattice cells. Struts are successively measured by XCT and focus variation (FV). A virtual volume correlation (V2C) method is presented where shape defect contained in XCT volumetric data is successively approached by modal decomposition relying on a generated defect basis. The modal decomposition approach is firstly validated by comparing its efficiency towards least square cylinder approximation. Then, correlation intrinsic parameters are found, by conducting 2-dimensional sensitivity studies to identify optimal V2C parameters. V2C is further applied to the entire XCT measurements for each considered strut. Comparisons between correlated envelopes and registered FV and XCT measurements are performed to numerically estimate RMS errors. Results show that RMS errors between correlated envelopes and registered measurements are in the same order as the XCT resolution. Conclusions can then be drawn regarding the ability of V2C to estimate lattice strut shape defect relying on an user-defined shape defect basis.},

keywords = {Tomographe},

pubstate = {published},

tppubtype = {article}

}

@article{Reyes2022,

title = {Microstructure characterization of high temperature mechanisms in a Nb\textendashTi\textendashSi alloy},

author = {David Reyes and Virgil Malard and Stefan Drawin and Alain Couret and Jean-Philippe Monchoux},

doi = {10.1016/j.intermet.2022.107509},

year  = {2022},

date = {2022-02-23},

journal = {Intermetallics},

volume = {144},

number = {107509},

abstract = {The deformation mechanisms of an Nb\textendash20Si\textendash25Ti\textendash6Al\textendash3Cr\textendash3Mo alloy deformed in compression at 1000 °C and at a strain rate of 10−4 s−1 have been investigated, using focused ion beam and transmission electron microscopy techniques. The initial microstructure of the alloy was constituted of a solid solution bcc Nbss matrix and of Nb5Si3 phases of β (tetragonal) and γ (hexagonal) crystallographic structures, with also hcp-Ti precipitates. As expected, the only phase which exhibited plastic deformation at 1000 °C was the Nbss matrix. Glide of dislocations has been observed, in planes compatible with {112} and {123} planes, or with cross-slip in {110} planes, as classically reported in bcc structures. Conversely, climb contribution has not been evidenced, probably because of rearrangement of the climbing dislocations in sub-boundaries. Fine δ-Nb11Si4 precipitates have been detected in the samples compressed at 1000 °C. Interactions of the δ-Nb11Si4 precipitates with the dislocations have been observed, which can potentially lead to strengthening of the Nbss phase.},

keywords = {Tour d'Atomisation},

pubstate = {published},

tppubtype = {article}

}

@article{Slama2022,

title = {Insight on precipitate evolution during additive manufacturing of stainless steels via in-situ heating-cooling experiments in a transmission electron microscope},

author = {Meriem Ben Haj Slama and Lluis Yedra and Eva H\'{e}ripr\'{e} and Manas Vijay Upadhyay},

url = {https://www.researchgate.net/publication/358571274_Insight_on_precipitate_evolution_during_additive_manufacturing_of_stainless_steels_via_in-situ_heating-cooling_experiments_in_a_transmission_electron_microscope},

doi = {10.1016/j.mtla.2022.101368},

year  = {2022},

date = {2022-02-14},

urldate = {2022-02-14},

journal = {Materialia},

number = {101368},

abstract = {During additive manufacturing of alloys, just after local heat-matter interactions, a molten material undergoes rapid solidification. Then, for the rest of the building time, it is subjected to cooling/heating cycles in the solid-state i.e., solid-state thermal cycling. The thermo-mechanical forces generated during solid-state thermal cycling can trigger a plethora of micro-mechanisms that can bring about significant microstructural changes that determine the eventual mechanical properties of as-built parts. In this work, the aim is to gain insight on solid-state thermal cycling-driven evolution of submicron-sized precipitates in an austenitic stainless steel using transmission electron microscopy. To that end, thin-film lamellae are extracted from a pre-built sample and subjected to different in-situ solid-state thermal cycles inside a transmission electron microscope. The solid-state thermal cycles are designed to understand the role of temperature amplitude and rates, number and type of thermal cycles, and post-process annealing on precipitate evolution. High angle annular dark field imaging and energy dispersive X-ray spectroscopy before and after each thermal cycle provide a deep insight on the contribution of different thermal cycling factors on the evolution of precipitate composition, size and morphology. Common trends include diffusion of Mn and Si from Mn-Si-rich oxides into the surrounding matrix, formation of Cr rings around oxide precipitates and S redistribution in non-oxide precipitates. Similar Cr rings and S distributions were also found in precipitates in as-built samples studied in (Upadhyay et al., Sci. Rep. 11 (2021) 10393), which strongly supports the representativeness of these results with respect to what occurs during additive manufacturing.},

keywords = {Helios, Titan},

pubstate = {published},

tppubtype = {article}

}

@article{Barr\`{e}s2021,

title = {Effect of grain boundary planes on radiation-induced segregation (RIS) at near Σ3 grain boundaries in Fe-Cr alloy under ion irradiation},

author = {Quentin Barr\`{e}s and Olivier Tissot and Estelle Meslin and Isabelle Mouton and Beno\^{i}t Arnal and Marie Loyer-Prost and Cristelle Pareige},

doi = {10.1016/j.matchar.2021.111676},

issn = {1044-5803},

year  = {2022},

date = {2022-02-01},

urldate = {2021-12-15},

journal = {Materials Characterization},

volume = {184},

number = {111676},

abstract = {Due to their good mechanical properties and corrosion resistance, Ferritic Martensitic and ODS steels are widely studied for applications in the next generation of nuclear reactor. Under irradiation, migration of point defects leads to different mechanisms including radiation-induced segregation (RIS). This type of segregation affects defect sinks such as grain boundaries (GB). Many parameters influence the amplitude of the RIS such as temperature, dose and chemical composition of the alloy. This paper presents the quantification of GB plane variation on RIS. Two different near Σ3 (60° 〈111〉) GB were investigated using EBSD and TKD for structural characterization and APT and STEM/EDXS for chemical quantification. This work revealed W-shaped profiles of Cr across GBs and a heterogeneous precipitation of Crsingle bondC rich particles in GBs planes after irradiation. Our work shows that not only the amplitude but also the sign of the Gibbsian Excess may be affected by the GB habit plane.},

keywords = {Titan},

pubstate = {published},

tppubtype = {article}

}

@article{Patte2021,

title = { A quasi-static poromechanical model of the lungs},

author = { C\'{e}cile Patte and Martin Genet and Dominique Chapelle},

editor = {Springer Science and Business Media Deutschland GmbH},

url = {https://hal.inria.fr/hal-03474200/document},

doi = {10.1007/s10237-021-01547-0},

issn = {16177959},

year  = {2022},

date = {2022-01-24},

urldate = {2021-12-10},

journal = {Biomechanics and Modeling in Mechanobiology},

abstract = {The lung vital function of providing oxygen to the body heavily relies on its mechanical behavior, and the interaction with its complex environment. In particular, the large compliance and the porosity of the pulmonary tissue are critical for lung inflation and air inhalation, and the diaphragm, the pleura, the rib cage and intercostal muscles all play a role in delivering and controlling the breathing driving forces. In this paper, we introduce a novel poromechanical model of the lungs. The constitutive law is derived within a general poromechanics theory via the formulation of lung-specific assumptions, leading to a hyperelastic potential reproducing the volume response of the pulmonary mixture to a change of pressure. Moreover, physiological boundary conditions are formulated to account for the interaction of the lungs with their surroundings, including a following pressure and bilateral frictionless contact. A strategy is established to estimate the unloaded configuration from a given loaded state, with a particular focus on ensuring a positive porosity. Finally, we illustrate through several realistic examples the relevance of our model and its potential clinical applications.},

keywords = {Cluster},

pubstate = {published},

tppubtype = {article}

}

@article{Cornet2022,

title = {In situ TEM Characterization of Phase Transformations and Kirkendall Void Formation During Annealing of a Cu\textendashAu\textendashSn\textendashCu Diffusion Bonding Joint},

author = {Louis Cornet and Lluis Yedra and Eva H\'{e}ripr\'{e} and V\'{e}ronique Aubin and Jean-Hubert Schmitt and Marie-Laurence Giorgi},

url = {https://rdcu.be/cFgxw},

doi = {10.1007/s11664-021-09390-w},

issn = {03615235},

year  = {2022},

date = {2022-01-18},

urldate = {2022-01-18},

journal = { J. Electron. Mater. },

abstract = {Diffusion bonding with Au, Cu and Sn is a technique that can be used to manufacture printed circuit boards. The mechanisms of reactive diffusion and Kirkendall void formation were studied in the Cu\textendashAu\textendashSn\textendashCu sandwich system. The initial thickness of the Au and Sn layers was a few micrometers, corresponding to 57 mol.% Au and 43 mol.% Sn. The experiments were conducted in situ in a transmission electron microscope (TEM). The TEM thin diffusion couple was heated to 240°C at a rate of 6.5°C/min and then held at 240°C for approximately 2 h. The Au-Sn interaction and progressive enrichment in Cu induce the nucleation and growth of different phases. After heating to 230°C, only binary intermetallic compounds are formed. Between 230°C and 240°C, the ternary phase B develops, replacing the other phases. Over longer periods at 240°C, phase B is progressively consumed on each interface with Cu and replaced with AuCu3. The diffusion path theory is used in the ternary Au-Cu-Sn diagram to analyze the chemical evolution of the system and the flux of elements through the interfaces. The nucleation and growth of Kirkendall voids are observed in parallel with reactive diffusion at both interfaces. The formation of Kirkendall voids appears to be primarily related to the growth of phase B. Mechanisms based on different diffusion rates for the elements are proposed to explain the formation of these voids.},

keywords = {Helios, Titan},

pubstate = {published},

tppubtype = {article}

}

@article{Jawale2021b,

title = {Catalytic hydrothiolation of alkenes and alkynes using bimetallic RuRh nanoparticles on carbon nanotubes},

author = {Dhanaji Jawale and Joel Tchuiteng-Kouatchou and Frederic Fossard and Frederic Miserque and Valerie Geertsen and Edmond Gravel and Eric Doris},

doi = {10.1039/D1GC04081B},

year  = {2021},

date = {2021-12-22},

journal = {Green Chemistry},

abstract = {A heterogeneous nanohybrid catalyst was assembled by immobilization of bimetallic ruthenium-rhodium nanoparticles on carbon nanotubes. The hybrid material was characterized using various techniques evidencing dense coating of the tubes with monodisperse particles. The catalyst was applied to the hydrothiolation of alkenes and alkynes and behaved superiorily, compared to monometallic counterparts. The system proved efficient under mild and sustainable conditions (low catalyst loading, room temperature, air atmosphere, green solvent) and could be recycled and reused with no loss of activity.},

keywords = {Titan},

pubstate = {forthcoming},

tppubtype = {article}

}

@article{Vrgo\v{c}2021b,

title = {Damage characterization in fiber reinforced polymer via Digital Volume Correlation},

author = {Ana Vrgo\v{c} and Zvonimir Tomi\v{c}evi\'{c} and Benjamin Smaniotto and Fran\c{c}ois Hild},

doi = {10.12989/csm.2021.10.6.545},

issn = {22342184},

year  = {2021},

date = {2021-12-01},

urldate = {2021-12-01},

journal = {Coupled Systems Mechanics},

volume = {10},

issue = {6},

pages = {545-560},

abstract = {An in situ experiment imaged via X-ray computed tomography was performed on a continuous glass fiber mat reinforced epoxy resin composite. The investigated dogbone specimen was subjected to uniaxial cyclic tension. The reconstructed scans (i.e., gray level volumes) were registered via Digital Volume Correlation. The calculated maximum principal strain fields and correlation residual maps exhibited strain localization areas within the material bulk, thus indicating damage inception and growth toward the specimen surface. Strained bands and areas of elevated correlation residuals were mainly concentrated in the narrowest gauge section of the investigated specimen, as well as on the specimen ligament edges. Gray level residuals were laid over the corresponding mesostructure to highlight and characterize damage development within the material bulk.},

keywords = {Tomographe},

pubstate = {published},

tppubtype = {article}

}

@article{Jawale2021,

title = {Carbon nanotube-polyoxometalate nanohybrids as efficient electro- catalysts for the hydrogen evolution reaction},

author = {Dhanaji V. Jawale and Fr\'{e}d\'{e}ric Fossard and Fr\'{e}d\'{e}ric Miserque and Val\'{e}rie Geertsen and Anne-Lucie Teillout and Pedro de Oliveira and Isra\"{e}l Mbomekall\'{e} and Edmond Gravel and Eric Doris},

doi = {10.1016/j.carbon.2021.11.046},

year  = {2021},

date = {2021-11-30},

journal = {Carbon},

volume = {188},

pages = {523-532},

abstract = {Electroactive hybrid nanomaterials were assembled by non-covalent, layer-by-layer deposition of tungsten-based polyoxometalates on carbon nanotubes. Chemical functionalization permitted access to nanotubes densely and homogeneously covered with polyoxometalates. Electrochemical characterisation of the nanohybrids highlighted the beneficial contribution of the nanotube platform to the overall stability of the immobilized POM species, and to the enhancement of their catalytic performances when applied to the hydrogen evolution reaction.},

keywords = {Titan},

pubstate = {published},

tppubtype = {article}

}

@article{Arnaud2021,

title = {Micromechanical tensile test investigation to identify elastic and toughness properties of thin nitride compound layers},

author = {Pierre Arnaud and Eva H\'{e}ripr\'{e} and Fr\'{e}d\'{e}ric Douit and V\'{e}ronique Aubin and Siegfried Fouvry and Romain Guiheux and Vincent Branger and Gr\'{e}gory Michel},

doi = {10.1016/j.surfcoat.2021.127303},

issn = {02578972},

year  = {2021},

date = {2021-09-15},

journal = {Surface and Coatings Technology},

volume = {421},

number = {127303},

keywords = {Helios},

pubstate = {published},

tppubtype = {article}

}

@article{Vrgo\v{c}2021,

title = {Application of different imaging techniques for the characterization of damage in fiber reinforced polymer},

author = {Ana Vrgo\v{c} and Zvonimir Tomi\v{c}evi\'{c} and Benjamin Smaniotto and Fran\c{c}ois Hild},

doi = {10.1016/j.compositesa.2021.106576},

issn = {1359835X},

year  = {2021},

date = {2021-08-02},

journal = {Composites Part A: Applied Science and Manufacturing},

volume = {150},

number = {106576},

abstract = {The heterogeneous and anisotropic nature of fiber reinforced polymers induces the initiation of various damage mechanisms at different scales. Even though full-field surface measurements may successfully track damage development, such approaches do not provide insights into the material bulk. The present work aims at comparing surface and bulk full-field measurements (via Digital Image/Volume Correlation) for a comprehensive analysis of polymer composite damage. Bulk measurements revealed that damage initiated at the microscale, thus contributing to surface localization phenomena. Full-field surface measurements could not capture the local strain states that the constituents were subjected to, which led to final fracture.},

keywords = {Tomographe},

pubstate = {published},

tppubtype = {article}

}

@article{Zerhouni2021,

title = {Quantifying the effect of two-point correlations on the effective elasticity of specific classes of random porous materials with and without connectivity},

author = {Othmane Zerhouni and S\'{e}bastien Brisard and Kostas Danas},

url = {https://www.sciencedirect.com/science/article/pii/S0020722521000677},

doi = {10.1016/j.ijengsci.2021.103520},

issn = {0020-7225},

year  = {2021},

date = {2021-06-27},

journal = {International Journal of Engineering Science},

volume = {166},

pages = {103520},

abstract = {It is well-known by now that the Hashin\textendashShtrikman bounds imply that the two-point correlation functions are not in general sufficient to estimate accurately the response of composites, especially when their underlying phases exhibit infinite contrast, e.g., porous materials. Starting from this longstanding, albeit qualitative result, this work investigates quantitatively the relevance of using two-point correlations to model the effective elastic properties of specific isotropic porous materials with and without connectivity. To achieve this in an unambiguous manner, we propose three different microstructures that share almost identical two-point statistics by design but are rather different morphologically. The choice of these microstructures is driven by their wide use in several practical problems ranging from polymers to geomaterials. The first microstructure is obtained by a random sequential adsorption (RSA) of non-overlapping, polydisperse, spherical and ellipsoidal voids oriented randomly in a unit-cell. The second one, termed connected random sequential adsorption (CRSA), is obtained from the first one by adding controlled connectivity via cylindrical channels of circular cross-section. The porosity resulting from connectivity is compensated by reducing the size of the existing voids to have the same overall porosity. Interestingly, we find that connectivity does not affect the corresponding two-point statistics. Finally, using as an input the numerical one- and two-point correlations of the RSA, we reconstruct a thresholded Gaussian random field (TGRF) microstructure. Using FFT numerical simulations, we show that the resulting effective elastic properties are very different for the three generated microstructures, despite them sharing nearly the same two-point correlation functions. We show, further, that the introduction of connectivity, and in particular the partial volume fraction of the connected channels, even small, affects strongly the resulting effective elasticity of the composite.},

keywords = {Cluster},

pubstate = {published},

tppubtype = {article}

}

@article{Upadhyay2021,

title = {Non-oxide precipitates in additively manufactured austenitic stainless steel},

author = {Manas Vijay Upadhyay and Meriem Ben Haj Slama and Steve Gaudez and Nikhil Mohanan and Lluis Yedra and Simon Hallais and Eva H\'{e}ripr\'{e} and Alexandre Tanguy},

url = {https://hal-polytechnique.archives-ouvertes.fr/hal-03221432/document},

doi = {10.1038/s41598-021-89873-2},

issn = {20452322},

year  = {2021},

date = {2021-05-17},

urldate = {2021-05-17},

journal = {Scientific Reports},

volume = {11},

number = {1},

pages = {10393},

abstract = {Precipitates in an austenitic stainless steel fabricated via any Additive Manufacturing (AM), or 3D printing, technique have been widely reported to be only Mn-Si-rich oxides. However, via Transmission Electron Microscopy (TEM) studies on a 316L stainless steel, we show that non-oxide precipitates (intermetallics, sulfides, phosphides and carbides) can also form when the steel is fabricated via Laser Metal Deposition (LMD)\textemdasha directed energy deposition-type AM technique. An investigation into their origin is conducted with support from precipitation kinetics and finite element heat transfer simulations. It reveals that non-oxide precipitates form during solidification/cooling at temperatures ≥ 0.75Tm (melting point) and temperature rates ≤ 105 K/s, which is the upper end of the maximum rates encountered during LMD but lower than those encountered during Selective Laser Melting (SLM)\textemdasha powder-bed type AM technique. Consequently, non-oxide precipitates should form during LMD, as reported in this work, but not during SLM, in consistency with existing literature.},

keywords = {Helios, Titan},

pubstate = {published},

tppubtype = {article}

}

@article{Dorn2021,

title = {Experiments and Numerical Implementation of a Boundary Value Problem Involving a Magnetorheological Elastomer Layer Subjected to a Nonuniform Magnetic Field},

author = {Charles Dorn and Laurence Bodelot and Kostas Danas},

url = {https://www.kostasdanas.com/kdanas_files/ArDBD2021_JAM.pdf},

doi = {10.1115/1.4050534},

issn = {0021-8936},

year  = {2021},

date = {2021-04-07},

journal = {Journal of Applied Mechanics},

volume = {88},

number = {7},

abstract = {This study investigates experimentally and numerically the response of a magnetorheological elastomer (MRE) layer placed atop an electromagnetic coil. The MRE layer is deflected upon application of a current in the coil, which creates highly nonuniform magnetic fields. Isotropic and transversely isotropic layers (i.e., containing chains of magnetic particles) are tested experimentally, and the isotropic layer exhibits the largest deflection. To enhance the energetic efficiency of the model device, an iron core is introduced inside the electromagnetic coil, thereby leading to an increase in the resulting magnetic field near the center of the MRE layer. In parallel, the boundary value problem\textemdashincluding the MRE layer, the coil, the core (if present) and the surrounding air\textemdashis modeled numerically. For this, a magneto-mechanical, vector potential-based variational formulation is implemented in a standard three-dimensional finite element model at finite strains. For the material description, a recently proposed analytical homogenization-guided model is used to analyze the MRE in the “coil-only” configuration. It is then employed to predict the response of the layer in the “coil plus core” configuration, thus circumventing the need for a separate material characterization procedure. The proposed numerical simulation strategy provides a deeper understanding of the underlying complexity of the magnetic fields and of their interaction with the MRE layer. This study also reveals the importance of modeling the entire setup for predicting the response of MRE materials and, as a result, constitutes a step toward designing more efficient MRE-based devices.},

keywords = {Cluster},

pubstate = {published},

tppubtype = {article}

}

@article{Liu2021,

title = {Constructing Hybrids Consisting of Porous Silica Particles and Carbon Nanotubes and their Polymer Composites},

author = {Yu Liu and Benhui Fan and Paul Haghi Ashtiani and Delong He and Jinbo Bai},

doi = {10.1007/s10443-021-09889-9},

issn = {0929189X},

year  = {2021},

date = {2021-03-31},

urldate = {2021-03-31},

journal = {Applied Composite Materials},

volume = {28},

number = {3},

pages = {705 - 715},

abstract = {One type of 3D hybrid structure has been successfully fabricated by a chemical vapor deposition method, which consisted of carbon nanotubes (CNTs) shell and porous spherical silica core. A biphase reaction was employed to synthesize the porous silica spheres. The pores had an average size of 19.5 ± 9.4 nm, which offered an ideal place for the deposition of catalyst during the CVD process and enhanced the adhesion force between the particles and CNTs. The sonication test indicated that the porous silica-CNTs hybrids had stronger adhesion force than that of the pristine silica-CNTs hybrids. Then, an ultralow fraction (0.1 wt.%) of the hybrids was incorporated into epoxy matrix to prepare the composites. The storage modulus of composites has improved greatly comparing to the pure epoxy and pristine silica-CNTs hybrids/epoxy composite. A possible reinforcement mechanism has been described to explain the phenomenon.},

keywords = {Titan},

pubstate = {published},

tppubtype = {article}

}

@article{Mukherjee2021,

title = {An explicit dissipative model for isotropic hard magnetorheological elastomers},

author = {Dipayan Mukherjee and Matthias Rambausek and Kostas Danas},

doi = {10.1016/j.jmps.2021.104361},

issn = {00225096},

year  = {2021},

date = {2021-02-22},

journal = {Journal of the Mechanics and Physics of Solids},

volume = {151},

number = {104361},

abstract = {Hard magnetorheological elastomers (h-MREs) are essentially two phase composites comprising permanently magnetizable metallic inclusions suspended in a soft elastomeric matrix. This work provides a thermodynamically consistent, microstructurally-guided modeling framework for isotropic, incompressible h-MREs. Energy dissipates in such hard-magnetic composites primarily via ferromagnetic hysteresis in the underlying hard-magnetic particles. The proposed constitutive model is thus developed following the generalized standard materials framework, which necessitates suitable definitions of the energy density and the dissipation potential. Moreover, the proposed model is designed to recover several well-known homogenization results (and bounds) in the purely mechanical and purely magnetic limiting cases. The magneto\textendashmechanical coupling response of the model, in turn, is calibrated with the aid of numerical homogenization estimates under symmetric cyclic loading. The performance of the model is then probed against several other numerical homogenization estimates considering various magneto\textendashmechanical loading paths other than the calibration loading path. Very good agreement between the macroscopic model and the numerical homogenization estimates is observed, especially for stiff to moderately-soft matrix materials. An important outcome of the numerical simulations is the independence of the current magnetization to the stretch part of the deformation gradient. This is taken into account in the model by considering an only rotation-dependent remanent magnetic field as an internal variable. We further show that there is no need for an additional mechanical internal variable. Finally, the model is employed to solve macroscopic boundary value problems involving slender h-MRE structures and the results match excellently with experimental data from literature. Crucial differences are found between uniformly and non-uniformly pre-magnetized h-MREs in terms of their pre-magnetization and the associated self-fields. },

keywords = {Cluster},

pubstate = {published},

tppubtype = {article}

}

@article{Toulouse2021,

title = {Patterning enhanced tetragonality in BiFeO3 thin films with effective negative pressure by helium implantation},

author = {Constance Toulouse and Johanna Fischer and S. Farokhipoor and Llu\'{i}s Yedra and Francesco Carla and Amelie Jarnac and E. Elkaim and Pierre Fertey and Jean-Nicolas Audinot and Tom Wirtz and Beatriz Noheda and V. Garcia and S. Fusil and I. Peral Alonso and Mael Guennou and Jens Kreisel},

editor = {American Physical Society},

doi = {10.1103/PhysRevMaterials.5.024404},

year  = {2021},

date = {2021-02-01},

journal = {Phys. Rev. Materials},

volume = {5},

number = {2},

pages = {024404},

abstract = {Helium implantation in epitaxial thin films is a way to control the out-of-plane deformation independently from the in-plane strain controlled by epitaxy. In particular, implantation by means of a helium microscope allows for local implantation and patterning down to the nanometer resolution, which is of interest for device applications. We present here a study of bismuth ferrite (BiFeO3) films where strain was patterned locally by helium implantation. Our combined Raman, x-ray diffraction, and transmission electron microscopy (TEM) study shows that the implantation causes an elongation of the BiFeO3 unit cell and ultimately a transition towards the so-called supertetragonal polymorph via states with mixed phases. In addition, TEM reveals the onset of amorphization at a threshold dose that does not seem to impede the overall increase in tetragonality. The phase transition from the R-like to T-like BiFeO3 appears as first-order in character, with regions of phase coexistence and abrupt changes in lattice parameters.},

keywords = {Titan},

pubstate = {published},

tppubtype = {article}

}

@article{deFrancqueville2021,

title = {Use of a micromechanical approach to understand the mechanical behavior of solid propellants},

author = {Foucault de Francqueville and Julie Diani and Pierre Gilormini and Aude Vandenbroucke},

editor = {Elsevier B.V.},

doi = {10.1016/j.mechmat.2020.103656},

issn = {01676636},

year  = {2021},

date = {2021-02-01},

journal = {Mechanics of Materials},

volume = {153},

abstract = {The development of new generations of propellants with better energetic properties may be hampered by unsatisfactory mechanical behaviors in terms of strength and toughness. A micromechanical approach is adopted to provide a better understanding of the existing links between the constitutive phase behaviors and the local damage, and the macroscopic mechanical behavior of these materials. Three model materials have been made and tested in uniaxial tension. The stress-strain responses were recorded while monitoring their volume changes that quantify the macroscopic damage. A qualitative description of the local damage was obtained thanks to scanning electron microscopy images of samples under loading. The micromechanical approach consists in finite elements analyses on periodic microstructures of non-regular polyhedral particles embedded in a soft matrix. An original microstructure generation tool has been developed specifically in order to obtain highly filled isotropic microstructures. Debonding at the matrix/filler interface was taken into account with a cohesive-zone model (CZM). The impact of the CZM parameters is discussed, in an effort to make the link between the CZM parameters and how the local damage appears and develops, and between the cohesive behavior and the shape of the macroscopic stress-stretch responses of the heterogeneous materials.},

keywords = {Cluster},

pubstate = {published},

tppubtype = {article}

}

@article{H\'{e}ripr\'{e}2021,

title = {FIB manufactured microstructures with low Coefficients of Thermal Expansion},

author = {Eva H\'{e}ripr\'{e} and Marwen Mehrez and Andrei Constantinescu},

doi = {10.1016/j.mechrescom.2021.103667},

issn = {0093-6413},

year  = {2021},

date = {2021-01-29},

journal = {Mechanics Research Communications},

pages = {103667},

keywords = {Helios},

pubstate = {published},

tppubtype = {article}

}

@article{Belkacemi-Rebrab2021,

title = {Striking effect of solute elements (Mn, Ni) on radiation-induced segregation/precipitation in iron-based model alloys},

author = {L.T. Belkacemi-Rebrab and E. Meslin and J-P. Crocombette and B. Radiguet and F. Lepr\^{e}tre and B. D\'{e}camps},

doi = {10.1016/j.jnucmat.2021.152807},

issn = {0022-3115},

year  = {2021},

date = {2021-01-27},

journal = {Journal of Nuclear Materials},

pages = {152807},

abstract = {The evolution of radiation damage in steels is a major issue for the safe operation of nuclear power plants. Mn and Ni contribution to the formation and evolution of microstructural features remains a controversial issue. The present study aims at investigating their effects on microstructure by irradiating undersaturated BCC Fe-3.3at.%Ni and Fe-2.8at.%Mn model alloys. Two different ion irradiation conditions have been applied to study the effect of irradiation dose rate in both of these Fe-based alloys at a temperature of 673 K. In all cases, irradiation promotes the formation of dislocation loops. In the FeNi alloy, radiation-induced segregation is observed on loops, leading to precipitation of a FCC phase in the low dose rate irradiation condition only. In the case of FeMn, even if no precipitation was revealed, highly enriched decorated dislocation loops are observed, with a higher Mn segregation at radiation defects than Ni.},

keywords = {Titan},

pubstate = {published},

tppubtype = {article}

}

@article{Vennat2021,

title = {The role of lateral branches on effective stiffness and local overstresses in dentin},

author = {Elsa Vennat and Asef Hemmati and Nicolas Schmitt and Denis Aubry},

doi = {10.1016/j.jmbbm.2021.104329},

issn = {1751-6161},

year  = {2021},

date = {2021-01-19},

journal = {Journal of the Mechanical Behavior of Biomedical Materials},

pages = {104329},

abstract = {The 3D microstructure of dentinal tissue, the main tissue of the tooth, is the subject of an increasingly comprehensive body of knowledge. The relationship between this microstructure and the mechanical behaviour of dentinal tissue remains, nonetheless, under question. This article proposes an original SEM analysis of dentin microstructure, accounting for lateral branches, and a mechanical model based on these findings. An interesting observation is that lateral branches have a dense collar, as do tubules. The diameter of these branches as well as a percentage area are quantified all along the depth of a dentin sample. We use these unprecedented data to build an orthotropic homogenized model of dentin. The heterogeneities of microstructure are taken into account using level-set functions. The results reveal that the lateral branches slightly influence the global homogenized elastic behavior of the dentin tissue, albeit creating stress concentration areas that are highly influenced by the inclination of the traction with respect to the tubule and branches.},

keywords = {Helios},

pubstate = {published},

tppubtype = {article}

}

@article{Neggers2021,

title = {Principal image decomposition for multi-detector backscatter electron topography reconstruction},

author = {Jan Neggers and Eva H\'{e}ripr\'{e} and Marc Bonnet and Denis Boivin and Alexandre Tanguy and Simon Hallais and Fabrice Gaslain and Elodie Rouesne and St\'{e}phane Roux},

editor = {Elsevier B.V.},

doi = {10.1016/j.ultramic.2020.113200},

isbn = {0304-3991},

year  = {2021},

date = {2021-01-15},

journal = {Ultramicroscopy},

pages = {113200},

abstract = {Scanning Electron Microscopes (SEMs) often generate images with a shaded appearance which gives a natural 3D impression. Ergo, quite a few methods to reconstruct the 3D surface topography from these using shape-from-shading methods are available in the literature. Here, a novel approach is discussed which uses BackScatter Electron (BSE) images from multiple detectors to reconstruct the topography. Classically, algorithms exist which resort to a quad-BSE detector setup. However, other detector configurations are often found in SEMs. A set of images of these non-conforming detectors still contains enough information to allow for reconstruction, but requires a more general algorithm to do so. This article discusses a method based on a modal decomposition of the principal image components. The resulting method is shown to be efficient and independent of the number of detectors or their orientation. In fact, the orientation is identified as part of the algorithm and thus requires very little calibration.},

keywords = {Helios},

pubstate = {published},

tppubtype = {article}

}

@article{Rambausek2021,

title = {Bifurcation of magnetorheological film\textendashsubstrate elastomers subjected to biaxial pre-compression and transverse magnetic fields},

author = {Matthias Rambausek and Kostas Danas},

doi = {10.1016/j.ijnonlinmec.2020.103608},

year  = {2021},

date = {2021-01-01},

journal = {International Journal of Non-Linear Mechanics},

volume = {128},

number = {103608},

abstract = {This work investigates the primary sinusoidal bifurcation wrinkling response of single- and multi-layered magnetorheological elastomer (MRE) film\textendashsubstrate systems subjected to combined transverse applied magnetic fields and in-plane biaxial pre-compression. A recently proposed continuum model that includes the volume fraction of soft-magnetic particles is employed to analyze the effect of the magnetic properties upon the bifurcation response of the system. The analysis is built in a highly versatile manner using a finite-element discretization approach along the direction of the applied magnetic field and Fourier expansions along the infinite in-plane layer directions. This allows for a seamless investigation of various multi-layered structures. First, we analyze the effect of biaxial pre-compression upon the critical magnetic field for a film\textendashsubstrate system and for various mechanical stiffness ratios. We observe a kink in the critical magnetic curves and a reflection in the corresponding wave numbers as they cross the equi-biaxial pre-compression regime. Subsequently, we consider a MRE film bonded to a MRE substrate and study the effect of the particle volume fraction ratios in those two parts. As a result, we obtain sharp pattern transitions, i.e., long-to-short wavelength changes with only minor perturbations of the applied pre-compression. The presence of a magnetic substrate changes qualitatively and quantitatively the bifurcation response of the film\textendashsubstrate system. Finally, we carry out a data-mining exercise to minimize the critical magnetic field at bifurcation by using three different topologies, i.e., a monolayer, a bilayer and a sandwich film. We find that the topologies resembling closely the monolayer one lead to the lowest critical magnetic fields for a given biaxial pre-compression.},

keywords = {Cluster},

pubstate = {published},

tppubtype = {article}

}

@article{Auger2020,

title = {Poynting Effects in Pantographic Metamaterial Captured via Multiscale DVC},

author = {Patrick Auger and Thomas Lavigne and Benjamin Smaniotto and Mario Spagnuolo and Francesco Dell'Isola and Fran\c{c}ois Hild},

editor = {SAGE Publications},

url = {https://hal.archives-ouvertes.fr/hal-02974410/document},

doi = {10.1177/0309324720976625},

year  = {2020},

date = {2020-12-06},

journal = { Journal of StrainAnalysis for Engineering Design},

abstract = {Metamaterials are often studied for their peculiar mechanical properties. However, few 4D studies were conducted on 3D printed pantographs. This study aims at analyzing an in situ torsion test in a lab tomograph. The acquired scans were used to measure displacement fields via digital volume correlation. The final goal was to analyze the deformation mechanisms of an Inconel pantograph and to rationalize potential Poynting effects.},

keywords = {Tomographe},

pubstate = {published},

tppubtype = {article}

}

@article{Yasothan2020,

title = {Morphological characterization of defects in all-ceramic crown adhesive layer},

author = {Yannick Yasothan and Kyo Shindo and Nicolas Schmitt and Elsa Vennat },

url = {https://www.tandfonline.com/doi/full/10.1080/10255842.2020.1816302},

doi = {10.1080/10255842.2020.1816302},

year  = {2020},

date = {2020-11-02},

journal = {Computer Methods in Biomechanics and Biomedical Engineering},

volume = {23},

keywords = {Tomographe},

pubstate = {published},

tppubtype = {article}

}

@article{Croom2020,

title = {Interlaboratory Study of Digital Volume Correlation Error Due to X-Ray Computed Tomography Equipment and Scan Parameters: an Update from the DVC Challenge},

author = {B.P. Croom and D. Burden and H. Jin and N.H. Vonk and J.P.M. Hoefnagels and B. Smaniotto and F. Hild and E. Quintana and Q. Sun and X. Nie and X. Li },

url = {https://link.springer.com/article/10.1007/s11340-020-00653-x#citeas},

doi = {10.1007/s11340-020-00653-x},

year  = {2020},

date = {2020-09-09},

journal = {Experimental Mechanics},

volume = {2020},

abstract = {Background

The quality of Digital Volume Correlation (DVC) full-field displacement measurements depends directly on the characteristics of the X-ray Computed Tomography (XCT) equipment, and scan procedures used to acquire the tomographic images.



Objective

We seek to experimentally study the effects of XCT equipment and tomographic scan procedures on the quality of these images for DVC analysis, and to survey the level of DVC error that may be achieved using standard XCT operating procedures.



Methods

Six participants in an interlaboratory study acquired high-quality XCT scans of a syntactic foam before and after rigid body motion. The resulting images were correlated using commercial DVC software to quantify error sources due to random image noise, reconstruction artifacts, as well as systematic spatial or temporal distortion.



Results

In the absence of rigid body motion, the standard deviation of the displacement measurements ranged from 0.012 to 0.043 voxels using a moderate subvolume size, indicating that subvoxel measurement resolution could readily be achieved with a variety of XCT equipment and scan recipes. Comparison of consecutive scans without rigid body motion showed transient dilatational displacement gradients due to self-heating of the X-ray source and/or thermal expansion of the foam. Evaluation of the scans after rigid body motion showed significant, machine-specific spatial distortion in the displacement fields of up to 0.5 voxels; new approaches to remove this error need to be developed.



Conclusions

Analysis of the scan protocols used in the interlaboratory study, as well as a complementary parametric sensitivity study, showed that the DVC error was strongly influenced by the XCT equipment, but could be mitigated by adjusting the total scan duration.},

keywords = {Tomographe},

pubstate = {published},

tppubtype = {article}

}

@article{Liu2020,

title = {*GO-CNTs hybrids reinforced epoxy composites with porous structure as microwave absorbers},

author = {Yu Liu and Delong He and Olivier Dubrunfaut and Anne Zhang and Hanlu Zhang and Lionel Pichon and Jinbo Bai},

doi = {10.1016/j.compscitech.2020.108450},

issn = {0266-3538},

year  = {2020},

date = {2020-09-06},

journal = {Composites Science and Technology},

volume = {200},

pages = {108450},

abstract = {Foam structures with epoxy as the matrix and both carbon nanotubes (CNTs) and their hybrids with graphene oxide (GO-CNTs) as absorbers were fabricated, and their microwave absorbing and electromagnetic properties were investigated in the frequency range of 1\textendash18 GHz. The fillers and bubbles were uniformly distributed in the composites. The complex permittivity and electrical conductivity of the composites increased as the fillers’ content increasing. The best performance of the reflection loss (RL) can be obtained for a foam structure with 0.5 wt% GO-CNTs, which had a RL peak value of −20dB with a −10 dB range of 5.3 GHz (10.8\textendash16.1 GHz). Multi-layered structures were also discussed in this work, a RL peak value of −40dB with a −10dB range of 7.1 GHz (9.9\textendash17 GHz) had been obtained by combining two foam structures, which are 2 mm thick 0.5 wt% GO-CNTs/epoxy and 1 mm thick 2.0 wt% GO-CNTs/epoxy. Furthermore, the −10dB range can reach 11.5 GHz (6.5\textendash18 GHz) when combining 2.6 mm thick 0.5 wt% GO-CNTs/epoxy and 1.3 mm thick 2.0 wt% GO-CNTs/epoxy.},

keywords = {Titan},

pubstate = {published},

tppubtype = {article}

}

@article{Hadjimichael2020,

title = {Domain structure and dielectric properties of metal-ferroelectric superlattices with asymmetric interfaces},

author = { Marios Hadjimichael and Yaqi Li and Llu\'{i}s Yedra and Brahim Dkhil and Pavlo Zubko},

editor = {American Physical Society},

url = {https://discovery.ucl.ac.uk/id/eprint/10111315/7/PhysRevMaterials.4.094415.pdf},

doi = {10.1103/PhysRevMaterials.4.094415},

year  = {2020},

date = {2020-09-01},

urldate = {2020-09-01},

journal = {Physical Review Materials},

volume = {4},

number = {9},

pages = {094415},

abstract = {PbTiO3/SrRuO3 superlattices deposited on SrTiO3 substrates are studied using a combination of x-ray diffraction, piezoresponse force microscopy, scanning transmission electron microscopy, transport measurements, and impedance spectroscopy. The superlattices are found to have two inequivalent interfaces resulting from differences in the growth modes for PbTiO3 and SrRuO3. X-ray diffraction measurements show that, despite being sandwiched between metallic SrRuO3 layers, the ferroelectric layers possess dense nanoscale domains. The observed domain sizes are comparable to those found in ferroelectric-dielectric systems, and they are attributed to the depolarizing field caused by the finite screening length of the SrRuO3-PbTiO3 interface. The macroscopic capacitance of the ultrathin PbTiO3 layers was measured, and its temperature dependence was found to be consistent with permittivity enhancement due to domain wall motion. ©2020 American Physical Society.},

keywords = {Titan},

pubstate = {published},

tppubtype = {article}

}

@article{Gong2020b,

title = {Nucleation and growth of oxide particles on a binary Fe-Mn (1 wt. %) alloy during annealing},

author = {Li Gong and Nathalie Ruscassier and Pascal Chr\'{e}tien and Paul Haghi-Ashtiani and Lluis Yedra and Marie-Laurence Giorgi},

editor = {Elsevier},

doi = {10.1016/j.corsci.2020.108952},

year  = {2020},

date = {2020-08-20},

journal = {Corrosion Science},

volume = {177},

number = {108952},

abstract = {An Fe-Mn (1 wt. %) alloy was annealed at 800 °C in N2-5 vol. % H2 with a dew point of −40 °C. The nucleation and growth of external selective oxides of MnO were characterized as a function of ferrite grain orientation. Nucleation occurs successively on Fe{110}, Fe{111} and Fe{100} at 650 to 700 °C. The oxides are faceted and their shape, size and surface density, measured accurately, are strongly dependent on the ferrite grain orientation. The oxides grow as the annealing time increases. New oxides are formed after 180 s at 800 °C. The associated external selective oxidation mechanisms are discussed.},

keywords = {Helios, Titan},

pubstate = {published},

tppubtype = {article}

}

@article{Pr\'{e}vost2020,

title = {Heteroepitaxial growth of sp2-hybridized boron nitride multilayer on nickel substrates by CVD: the key role of the substrate orientation},

author = {H. Pr\'{e}vost and Amandine Andrieux-Ledier and Nelly Dorval and Fr\'{e}d\'{e}ric Fossard and Jean-S\'{e}bastien M\'{e}rot and L\'{e}onard Schu\'{e} and Julien Barjon and Annick Loiseau},

doi = {10.1088/2053-1583/aba8ad},

year  = {2020},

date = {2020-08-18},

journal = {2D Materials},

volume = {7},

number = {4},

abstract = {sp2-hybridized boron nitride is identified as a strategic material for many purposes related to the integration of graphene and two-dimensional materials in devices and the fabrication of van der Waals heterostructures. Thus, it becomes mandatory to have scalable synthesis and characterization procedures for providing suitable and reliable boron nitride material according to these identified needs. We report here on the growth of sp2-hybridized boron nitride film on polycrystalline nickel substrate by chemical vapor deposition with borazine as precursor. We propose a complete study of the influence of the underlying nickel grain orientation on the BN structure layers, in terms of thickness, crystallographic orientation, domain size and stacking. We show the heteroepitaxial growth of continuous, single crystalline hexagonal boron nitride multilayer film on nickel (111)-like grains. We highlight its ABC stacking sequence with AB stacking faults and show how it impacts the Raman and cathodoluminescence spectra.},

keywords = {Helios},

pubstate = {published},

tppubtype = {article}

}

@article{Salem2020,

title = {Mechanical Behavior Characterization of a Stainless Steel Dissimilar Metal Weld Interface : In-situ Micro-Tensile Testing on Carburized Martensite and Austenite},

author = {Ghassen Ben Salem and Eva H\'{e}ripr\'{e} and Philippe Bompard and St\'{e}phane Chapuliot and Arnaud Blouin and Cl\'{e}mentine Jacquemoud},

editor = {Springer},

doi = {10.1007/s11340-020-00633-1},

year  = {2020},

date = {2020-07-27},

journal = {Experimental Mechanics},

abstract = {Background

Stainless Steel Dissimilar Metal Welds (SS DMW) between low-alloy steel 18MND5 and austenitic 316L stainless steel are critical junctions in the currently operating reactors because of their heterogeneous microstructure and mechanical properties. The presence of a narrow hard layer of carburized martensite and austenite in the ferritic-austenitic interface creates an important hardness gradient which affects the crack behavior of the SS DMW.



Objective

In order to evaluate the plastic properties of this hard layer, a micro tensile testing method was developed.



Methods

Tensile specimens of 15 x 80 x 6 μm were extracted from the martensitic and carburized austenitic layers by focused ion beam (FIB) micro-processing and tested using an in-situ tensile testing device. A platinum FIB deposition was used to measure local strain in the specimen during the test through digital image correlation (DIC). Isotropic elasto-plastic constitutive laws for the martensite and carburized austenite were obtained from the true strain-stress curves calculated from the micro-tensile tests.



Results

It was found that the corresponding plastic properties were in a good agreement with nanoindentation measurements and with values obtained from macroscopic tensile tests on crossweld specimens machined perpendicularly to the ferritic-austenitic interface and characterized using laser beam local diameter measurements.



Conclusions

In-situ tensile testing is a promising technique for plastic behavior characterization of small scale materials and local hard layers in dissimilar metal welds.},

keywords = {Helios},

pubstate = {published},

tppubtype = {article}

}