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108 results on '"Mohamed Gouné"'

1. Dataset of mechanical properties and electrical conductivity of copper-based alloys

Author: Stéphane Gorsse, Mohamed Gouné, Wei-Chih Lin, and Lionel Girard
Subjects: Science
Abstract: Abstract This article presents a collection of data on approximately 150 copper-based alloys. The data compilation is based on articles published since 1993 and consists of about 1830 records. Each record contains a unique set of descriptors, such as composition and processing route, and targets, including properties such as hardness, yield strength, ultimate tensile strength, and electrical conductivity. The dataset includes information on the composition in mass percent of 20 alloying elements, and hundreds of temperature-time thermal treatments and thermomechanical conditions. The database is continually updated and hosted on an open data repository. Some of the data are presented graphically in the article to aid interpretation. This study intends to promote the identification of more sustainable alternatives to Cu-Be alloys, which is particularly relevant in developing non-toxic and environmentally-friendly alloys.
Published: 2023
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2. Morphological and Dimensional Evolution of Nanosized Amorphous Silicon Nitride in α-Fe: Diffusional and Elastic Effects

Author: Sylvie Bordère, Hugo-Paul Van Landeghem, Abdelkrim Redjaïmia, and Mohamed Gouné
Subjects: nitrogen steels, amorphous-precipitate, nitride, morphological stability, diffusion, internal stresses, Mining engineering. Metallurgy, TN1-997
Abstract: We present a detailed analysis based on both experimental and 3D modelling approaches of the unique silicon nitride precipitation sequence observed in ferritic Fe-Si alloys upon nitriding. At 570 °C, Si3N4 silicon nitride was shown to form as an amorphous phase into α-Fe ferrite matrix, which is morphologically unstable over time. Precipitates nucleated with a spheroidal shape, then developed a cuboidal shape for intermediate sizes and octapod-like morphology for a longer time. Using transmission electron microscopy, we show that the transition between spheroid and cuboid morphology depended on particle size and resulted from competition between interfacial energy and elastic strain energy. The resulting morphology was then shown to be a cuboid shape whose faces were always parallel to the {100} planes of the α-Fe; the directions of the matrix corresponded to the elastically soft directions. There was a critical size of around 45 nm for which the transition between the cuboid shape and the octapod-like morphology took place. This was characterised by a transformation of quasi-flat facets into concave ones and the development of lobes in the directions of the bcc crystal. To better assess the kinetic effects of diffusion fields and internal stresses on the morphological instability observed, an original 3D model that explicitly coupled phase transformations and mechanical fields was developed and applied. The latter, validated on the basis of model cases, was shown to be able to describe the time-evolution of both chemical and mechanical fields and their interactions in diffusive mass transport. Using a model system, it was shown that the concentration field around the precipitates and the internal stresses played opposing roles in the cuboid to octapod-like morphological instability. This work gives some clarification regarding the morphological evolution of amorphous Si3N4 precipitates, an important point for controlling the mechanical properties of nitrogen steels.
Published: 2024
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3. Novel lead-free BCZT-based ceramic with thermally-stable recovered energy density and increased energy storage efficiency

Author: Zouhair Hanani, Soukaina Merselmiz, M'barek Amjoud, Daoud Mezzane, Mohammed Lahcini, Jaafar Ghanbaja, Matjaž Spreitzer, Damjan Vengust, Mimoun El Marssi, Igor A. Luk'yanchuk, Zdravko Kutnjak, Brigita Rožič, and Mohamed Gouné
Subjects: Lead-free ceramics, Low temperature, Piezoelectric, Thermal stability, Energy storage, Nanostructuration, Materials of engineering and construction. Mechanics of materials, TA401-492
Abstract: The eco-responsible lead-free piezoelectric ceramics have been intensively searched for more than a decade, however, the final goal to replace toxic ceramics like lead zirconate titanate (PZT) with lead-free compounds, having comparable or even better performance has not yet been reached. In this road, the lead-free ceramics Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT), possessing excellent dielectric, ferroelectric, and piezoelectric properties are regarded as serious candidates for the PZT replacement. Besides, nanostructuring BCZT is of paramount importance to enhance these functionalities even more. Here, BCZT multipodes are designed by template-growth hydrothermal synthesis using hydrogen zirconate titanate nanowires. We demonstrate that the fabricated BCZT multipodes exhibit high dielectric permittivity of 5300 with a temperature stability coefficient of ±5.9% between 20 and 140 °C. A significant recovered energy density of 315.0 mJ/cm3 with high thermal stability and high energy storage efficiency of 87.4%, and enhanced large-signal piezoelectric coefficient d33∗ (310 pm/V) are found. Compared to the traditional BCZT ceramics reported in the literature, relying on high-temperature processing, our sample exhibits boosted energy storage parameters at a much lower temperature. These outcomes may offer a new strategy to tailor eco-responsible relaxor ferroelectrics toward superior energy storage performance for ceramic capacitor applications.
Published: 2022
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4. Enhanced dielectric and electrocaloric properties in lead-free rod-like BCZT ceramics

Author: Zouhair Hanani, Soukaina Merselmiz, Abdelaadim Danine, Nicolas Stein, Daoud Mezzane, M’barek Amjoud, Mohammed Lahcini, Yaovi Gagou, Matjaz Spreitzer, Damjan Vengust, Zdravko Kutnjak, Mimoun El Marssi, Igor A. Luk’yanchuk, and Mohamed Gouné
Subjects: lead-free Ba0.85Ca0.15Zr0.10Ti0.90O3 (BCZT), rod-like Ba0.85Ca0.15Zr0.10Ti0.90O3 (BCZT), dielectric, ferroelectric, electrocaloric effect, Clay industries. Ceramics. Glass, TP785-869
Abstract: Abstract Ba0.85Ca0.15Zr0.10Ti0.90O3 (BCZT) lead-free ceramics demonstrated excellent dielectric, ferroelectric, and piezoelectric properties at the morphotropic phase boundary (MPB). So far, to study the effect of morphological changes on dielectric and ferroelectric properties in lead-free BCZT ceramics, researchers have mostly focused on the influence of spherical grain shape change. In this study, BCZT ceramics with rod-like grains and aspect ratio of about 10 were synthesized by surfactant-assisted solvothermal route. X-ray diffraction (XRD) and selected area electron diffraction (SAED) performed at room temperature confirm the crystallization of pure perovskite with tetragonal symmetry. Scanning electron microscopy (SEM) image showed that BCZT ceramics have kept the 1D rod-like grains with an average aspect ratio of about 4. Rod-like BCZT ceramics exhibit enhanced dielectric ferroelectric (ɛr = 11,906, tanδ = 0.014, P r = 6.01 μgC/cm2, and E c = 2.46 kV/cm), and electrocaloric properties (ΔT = 0.492 K and gZ = 0.289 (K·mm)/kV at 17 kV/cm) with respect to spherical BCZT ceramics. Therefore, rod-like BCZT lead-free ceramics have good potential to be used in solid-state refrigeration technology.
Published: 2020
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5. Additive manufacturing of metals: a brief review of the characteristic microstructures and properties of steels, Ti-6Al-4V and high-entropy alloys

Author: Stéphane Gorsse, Christopher Hutchinson, Mohamed Gouné, and Rajarshi Banerjee
Subjects: Additive manufacturing, 3D printing, microstructure, Ti alloys, steels, high entropy alloys, Materials of engineering and construction. Mechanics of materials, TA401-492, Biotechnology, TP248.13-248.65
Abstract: We present a brief review of the microstructures and mechanical properties of selected metallic alloys processed by additive manufacturing (AM). Three different alloys, covering a large range of technology readiness levels, are selected to illustrate particular microstructural features developed by AM and clarify the engineering paradigm relating process–microstructure–property. With Ti-6Al-4V the emphasis is placed on the formation of metallurgical defects and microstructures induced by AM and their role on mechanical properties. The effects of the large in-built dislocation density, surface roughness and build atmosphere on mechanical and damage properties are discussed using steels. The impact of rapid solidification inherent to AM on phase selection is highlighted for high-entropy alloys. Using property maps, published mechanical properties of additive manufactured alloys are graphically summarized and compared to conventionally processed counterparts.
Published: 2017
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6. Microstructure Evolution and Competitive Reactions during Quenching and Partitioning of a Model Fe–C–Mn–Si Alloy

Author: Samy Aoued, Frédéric Danoix, Sébastien Y.P. Allain, Steve Gaudez, Guillaume Geandier, Jean-Christophe Hell, Michel Soler, and Mohamed Gouné
Subjects: steels, quenching and partitioning, partitioning, high-energy x-ray diffraction, atom probe tomography, Mining engineering. Metallurgy, TN1-997
Abstract: The mechanisms behind the carbon enrichment of austenite during quenching and partitioning are still a matter of debate. This work investigates the microstructural evolution during the quenching and partitioning of a model Fe−C−Mn−Si alloy by means of in situ high energy X-ray diffraction (HEXRD) atom probe tomography, and image analysis. The ultra-fast time-resolved quantitative information about phase transformations coupled with image analysis highlights the formation of carbide-free BCT bainite, which is formed within a very short range during the reheating and partitioning step. Its transformation rate, which is a better indicator than the intrinsic volume fraction, depends on the quenching temperature (QT). It is shown to decrease with decreasing QT, from 45% at QT = 260 °C to 20% at QT = 200 °C. As a consequence, a significant part of the carbon enrichment observed in austenite can be attributed to bainite transformation. Furthermore, a large part of carbon was shown to be trapped into martensite. Both the formation of Fe2.6C iron carbides and the segregation of carbon on lath boundaries in martensite were highlighted by atom probe tomography. The energy for carbon segregation was determined to be 0.20 eV, and the carbon concentration on the lath boundaries was obtained to be around 25 at %. Therefore, the carbon enrichment of austenite is the result of competitive reactions such as carbon partitioning from martensite, bainite transformation, and carbon trapping in martensite.
Published: 2020
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7. QUANTITATIVE ANALYSIS OF BANDED STRUCTURES IN DUAL-PHASE STEELS

Author: Benoit Krebs, Alain Hazotte, Lionel Germain, and Mohamed Gouné
Subjects: banded structure, covariance function, quantitative microscopy, steel, Medicine (General), R5-920, Mathematics, QA1-939
Abstract: Dual-Phase (DP) steels are composed of martensite islands dispersed in a ductile ferrite matrix, which provides a good balance between strength and ductility. Current processing conditions (continuous casting followed by hot and cold rolling) generate 'banded structures' i.e., irregular, parallel and alternating bands of ferrite and martensite, which are detrimental to mechanical properties and especially for in-use properties. We present an original and simple method to quantify the intensity and wavelength of these bands. This method, based on the analysis of covariance function of binary images, is firstly tested on model images. It is compared with ASTM E-1268 standard and appears to be more robust. Then it is applied on real DP steel microstructures and proves to be sufficiently sensitive to discriminate samples resulting from different thermo-mechanical routes.
Published: 2011
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8. Effects of Q&P Processing Conditions on Austenite Carbon Enrichment Studied by In Situ High-Energy X-ray Diffraction Experiments

Author: Sébastien Yves Pierre Allain, Guillaume Geandier, Jean-Christophe Hell, Michel Soler, Frédéric Danoix, and Mohamed Gouné
Subjects: steel, martensite, bainite, Q&amp, synchrotron, HEXRD, TRIP, Mining engineering. Metallurgy, TN1-997
Abstract: We report the first ultra-fast time-resolved quantitative information on the quenching and partitioning process of conventional high-strength steel by an in situ high-energy X-ray diffraction (HEXRD) experiment. The time and temperature evolutions of phase fractions, their carbon content, and internal stresses were determined and discussed for different process parameters. It is shown that the austenite-to-martensite transformation below the martensite start temperature Ms is followed by a stage of fast carbon enrichment in austenite during isothermal holding at both 400 and 450 °C. The analysis proposed supports the concurrent bainite transformation and carbon diffusion from martensite to austenite as the main mechanisms of this enrichment. Furthermore, we give evidence that high hydrostatic tensile stresses in austenite are produced during the final quenching, and must be taken into account for the estimation of the carbon content in austenite. Finally, a large amount of carbon is shown to be trapped in the microstructure.
Published: 2017
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9. The paradigm of the filler's dielectric permittivity and aspect ratio in high-k polymer nanocomposites for energy storage applications

Author: Zouhair Hanani, Daoud Mezzane, M’barek Amjoud, Mohammed Lahcini, Matjaž Spreitzer, Damjan Vengust, Arash Jamali, Mimoun El Marssi, Zdravko Kutnjak, and Mohamed Gouné
Subjects: Materials Chemistry, General Chemistry
Abstract: The energy storage performances in ceramic/polymer nanocomposites are mainly linked to the dielectric permittivity and the aspect ratio of the nanofiller, though, the morphological effect (aspect ratio) is greater than the permittivity one.
Published: 2022
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10. Low-temperature synthesis and characterization of lead-free BaTi0.89Sn0.11O3 piezoelectric powders

Author: Marwa Zahid, Ouissal Kharraz, M'barek Amjoud, Daoud Mezzane, Mohamed Gouné, Khalid Hoummada, Ismael Saadoune, Sebastien Fourcade, Pierre Stocker, Brigita Rožič, Zdravko Kutnjak, Mimoun El Marssi, Laboratoire des Matériaux Innovants, Energie et Développement Durable [Marrakech] (IMED-Lab ), Faculté des Sciences et Techniques Marrakech (FSTG), Université Cadi Ayyad [Marrakech] (UCA)-Université Cadi Ayyad [Marrakech] (UCA), Laboratoire de Physique de la Matière Condensée - UR UPJV 2081 (LPMC), Université de Picardie Jules Verne (UPJV), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie Radicalaire (ICR), Aix Marseille Université (AMU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Jozef Stefan Institute [Ljubljana] (IJS), and The financial support of the European Union Horizon 2020 Research and Innovation actions MSCA-RISE-ENGIMA (No. 778072) and MSCA-RISE-MELON (No. 872631) and ARRS project J1-9147 and program P1-0125 and CNRST Priority Program PPR 15/2015 and the ministry of Science and Higher Education of the Russian Federation, grant agreement No 075-15-2021-953.
Subjects: Low-temperature chemistry, Barium stannate titanate, Sol-gel Hydrothermal, [CHIM.MATE]Chemical Sciences/Material chemistry, Lead-free piezoelectric
Abstract: International audience; Barium stannate titanate (BaTi0.89Sn0.11O3, BTS11) is one of the reported lead-free materials that exhibit high dielectric and piezoelectric properties near ambient temperature. In this work, BTS11 powders were elaborated via a soft chemistry method at very low temperatures using two synthesized approaches combining sol-gel and hydrothermal processes. In the first approach, the effect of the barium precursor on the purity and the crystallinity of the BTS11 powders were studied. In contrast, in the second approach, the influence of the hydrothermal temperature on the BTS11 proprieties was analyzed. As a result, pure and uniform fine powders were obtained at 180 °C. The appropriate mass fraction of BTS11, which leads to high suspension stability in water, is below 3%. These eco-friendly and pure piezoelectric powders can be used without further heat-treatment in several applications such as lead-free piezoelectric decontamination of organic pollutants and photocatalyst, hydrogen generation and as fillers in flexible nanocomposites nano-generators for energy harvesting and energy storage.
Published: 2022
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11. Écrouissage et propriétés en traction

Author: Mohamed GOUNÉ and Olivier BOUAZIZ
Abstract: Ce chapitre traite des interactions entre les dislocations mobiles et les différents obstacles présents dans la microstructure des aciers à très haute résistance. Les analyses effectuées basées sur une approche microscopique et des données expérimentales permettent de mieux appréhender les liens qui existent entre les paramètres microstructuraux, l’écrouissage et les propriétés en traction.
Published: 2022
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12. Enhanced near-ambient temperature energy storage and electrocaloric effect in the lead-free BaTi0.89Sn0.11O3 ceramic synthesized by sol–gel method

Author: Marwa Zahid, Youness Hadouch, M’barek Amjoud, Daoud Mezzane, Mohamed Gouné, Khalid Hoummada, Abdelhadi Alimoussa, Anna G. Razumnaya, Brigita Rožič, Zdravko Kutnjak, Laboratoire des Matériaux Innovants, Energie et Développement Durable [Marrakech] (IMED-Lab ), Faculté des Sciences et Techniques Marrakech (FSTG), Université Cadi Ayyad [Marrakech] (UCA)-Université Cadi Ayyad [Marrakech] (UCA), Laboratoire de Physique de la Matière Condensée - UR UPJV 2081 (LPMC), Université de Picardie Jules Verne (UPJV), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Faculty of Physics, Southern Federal University, Jozef Stefan Institute [Ljubljana] (IJS), and This work was supported by CNRST Priority Program PPR 15/2015, by the European Union's Horizon 2020 research and Innovation actions MSCA-RISE-ENGIMA (No. 778072) and MSCA-RISEMELON (No. 872631) and ARRS project J1-9147, and by the ministry of Science and Higher Education of the Russian Federation, grant agreement No 075-15-2021-953.
Subjects: Lead-free, energy storage, barium stannate titanate, ambient temperature, [CHIM.MATE]Chemical Sciences/Material chemistry, Electrical and Electronic Engineering, Condensed Matter Physics, sol-gel process, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, electrocaloric effect
Abstract: International audience; Lead-free perovskite materials with high performance have high potential in clean energy storage applications and developments of electrocaloric devices. In this work, we report structural, dielectric, ferroelectric properties, energy storage and electrocaloric effectnear the ambient temperature in barium stannate titanate (BaTi 0.89 Sn 0.11 O 3, BTS 11) ceramic prepared by a sol-gel method. The formation of a single perovskite structure was confirmed using the X-ray diffraction analysis. An average grain size of 18.5µm was found by the mean of the SEM micrograph with a density of 5.91 g/cm 3 .The presence of the multiphase at very near ambient temperature was proved using temperature-dependent micro-Raman measurements and differential scanning calorimetry. The BTS 11 ceramic exhibits a high dielectric constant of 15460and a low dielectric loss (
Published: 2022
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13. Thermally-stable high energy storage performances and large electrocaloric effect over a broad temperature span in lead-free BCZT ceramic

Author: Igor A. Luk'yanchuk, Mimoun El Marssi, Brigita Rožič, Mohammed Lahcini, Andrey Ragulya, Zouhair Hanani, Zdravko Kutnjak, Mohamed Gouné, Daoud Mezzane, M'barek Amjoud, Soukaina Merselmiz, Andraž Bradeško, Université Cadi Ayyad [Marrakech] (UCA), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Jozef Stefan Institute [Ljubljana] (IJS), Mohammed VI Polytechnic University [Marocco] (UM6P), Laboratoire de Physique de la Matière Condensée - UR UPJV 2081 (LPMC), Université de Picardie Jules Verne (UPJV), I.N. Frantsevich Institute for Problems of Materials Science of NAS of Ukraine (IPMS), National Academy of Sciences of Ukraine (NASU), Physics Faculty, Southern Federal University [Rostov-on-Don] (SFEDU), and The authors gratefully acknowledge the generous financial support of CNRST Priority Program PPR 15/2015 and the European Union Horizon 2020 Research and Innovation actions MSCA-RISE-ENGIMA (No. 778072) and MSCA-RISE-MELON (No. 872631). Z. K. and B. R. acknowledge Slovenian Research Agency grant J1-9147 and program P1-0125.
Subjects: 010302 applied physics, Phase transition, Materials science, General Chemical Engineering, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, General Chemistry, Dielectric, Atmospheric temperature range, 021001 nanoscience & nanotechnology, 01 natural sciences, 7. Clean energy, Ferroelectricity, Energy storage, visual_art, 0103 physical sciences, Electrocaloric effect, visual_art.visual_art_medium, Dielectric loss, Ceramic, Composite material, 0210 nano-technology
Abstract: International audience; Ba0.85Ca0.15Zr0.10Ti0.90O3 (BCZT) relaxor ferroelectric ceramics exhibit enhanced energy storage and electrocaloric performances due to their excellent dielectric and ferroelectric properties. In this study, the temperature-dependence of the structural and dielectric properties, as well as the field and temperature-dependence of the energy storage and the electrocaloric properties in BCZT ceramics elaborated at low-temperature hydrothermal processing are investigated. X-ray diffraction and Raman spectroscopy results confirmed the ferroelectric–paraelectric phase transition in the BCZT ceramic. At room temperature and 1 kHz, the dielectric constant and dielectric loss reached 5000 and 0.029, respectively. The BCZT ceramic showed a large recovered energy density (Wrec) of 414.1 mJ cm−3 at 380 K, with an energy efficiency of 78.6%, and high thermal-stability of Wrec of 3.9% in the temperature range of 340–400 K. The electrocaloric effect in BCZT was explored via an indirect approach following the Maxwell relation at 60 kV cm−1. The significant electrocaloric temperature change of 1.479 K at 367 K, a broad temperature span of 87 K, an enhanced refrigerant capacity of 140.33 J kg−1, and a high coefficient of performance of 6.12 obtained at 60 kV cm−1 make BCZT ceramics potentially useful coolant materials in the development of future eco-friendly solid-state refrigeration technology.
Published: 2020
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14. Time-evolution of microstructure and mechanical behaviour of double annealed medium Mn steel

Author: Artem Arlazarov, Olivier Bouaziz, Frédéric Kegel, Alain Hazotte, Mohamed Gouné, ArcelorMittal Maizières Research SA, ArcelorMittal, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), Labex DAMAS, and Université de Lorraine (UL)
Subjects: 010302 applied physics, Fresh martensite . Retained austenite, Materials science, Annealing (metallurgy), Intercritical annealing, Mechanical Engineering, Time evolution, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, 01 natural sciences, Medium Mn steel, Tensile behavior, Mechanics of Materials, Double annealing, 0103 physical sciences, Transformation induced plasticity (TRIP), General Materials Science, Composite material, Tensile behavior . Strain hardening rate, 0210 nano-technology, Holding time
Abstract: International audience; Cold rolled 0.1C-4.7Mn (wt-%) steel was submitted to double annealing. The holding time of second intercritical annealing at 650°C was varied between 3 min and 30 h. Tensile behavior after each treatment was measured and analysed. Microstructure characterisation was performed using field emission gun scanning electron microscope, transmission electron microscope and saturation magnetisation method. Moreover, interrupted tensile tests were done to obtain the kinetics of austenite destabilisation during straining. An important effect of soaking time on the microstructure and associate mechanical properties was revealed and analysed. Considering thermal and mechanical stability of retained austenite, the optimum combination of phases, providing the best strength-ductility balance, was found after 2 h holding.
Published: 2019
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15. New Advanced High Strength Steels : Optimizing Properties

Author: Mohamed Goune, Thierry Iung, Jean-Hubert Schmitt, Mohamed Goune, Thierry Iung, and Jean-Hubert Schmitt
Subjects: Steel, High strength
Abstract: In recent years, significant developments have been made to increase the mechanical strength of steels in order to reduce the overall weight of structures, particularly in motor vehicles. Depending on the application, the increase in strength should not be at the expense of forming and in-use properties. The development of ultra-high strength steels requires a search for new trade-offs between these properties in order to optimize the final microstructure. New Advanced High Strength Steels analyzes the interactions between tensile mechanical properties and properties such as work hardening, anisotropy, resistance to rupture, fatigue life, corrosion resistance, crashworthiness, edge retention, hydrogen resistance and weldability. It also examines the links between the microstructural parameters of high-strength steels and the properties mentioned above. It highlights the metallurgical developments that have been necessary for the emergence of these new generations of steels. The book concludes with a look ahead to future developments in ultra-high strength steels.
Published: 2024

16. Dual-Phase Steels: The First Family of Advanced High Strength Steels

Author: Irina Pushkareva, Mohamed Gouné, Colin Scott, Julien Teixeira, Sébastien Allain, Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Canmet MATERIALS, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), and Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Metallurgy, 0211 other engineering and technologies, 02 engineering and technology, 021001 nanoscience & nanotechnology, Microstructure, Dual (category theory), [SPI.MAT]Engineering Sciences [physics]/Materials, Martensite, Ferrite (iron), Formability, 0210 nano-technology, Ductility, Composite microstructure, 021102 mining & metallurgy
Abstract: International audience; Dual-Phase steels have been marketed since the early 1990s and are widely used in the sector of automotive and truck construction. They make up the majority of so-called modern or first-generation AHSS (Advanced High Strength Steels). The superior balance between strength, formability and ductility of DP steels comes from their particular composite microstructure, consisting mainly of ferrite and martensite. This article traces first the history of DP steels from their discovery in the 1960s to the most recent industrial developments. It then addresses current knowledge about the link between the microstructure and mechanical properties of these alloys. The mechanisms governing their microstructure morphogenesis are described in a third part. During those discussions, the contributions of metallurgical and micromechanical modeling in DP science shall be highlighted. Finally, the active fields of research and the anticipated developments of DP technologies will be evoked.
Published: 2020
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17. Fabrication additive de pièces en titane par fusion sélective de lit de poudre

Author: Stéphane Gorsse, Charlotte de Formanoir, Stéphane Godet, S. Bordère, and Mohamed Gouné
Abstract: Cet article traite des microstructures et du comportement mecanique de l’alliage Ti-6Al-4V mis en œuvre par fabrication additive, en comparaison avec ses equivalents corroyes. Apres une presentation des principales transformations de phases au sein de l’alliage Ti-6Al-4V, le lien entre procede, microstructure et proprietes mecaniques, les mecanismes de formation des defauts et les effets des post traitements sont decrits.
Published: 2020
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18. Structural, dielectric, and ferroelectric properties of lead-free BCZT ceramics elaborated by low-temperature hydrothermal processing

Author: Anna G. Razumnaya, Yaovi Gagou, Mohamed Gouné, Brigita Rozic, Zouhair Hanani, Khalid Hoummada, C. Perrin, M'barek Amjoud, Mimoun El Marssi, Adnane Bouzina, Zdravko Kutnjak, Daoud Mezzane, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Cadi Ayyad [Marrakech] (UCA), Laboratoire de Matière Condensée et Nanostructures (LMCN), Faculté des Sciences et Techniques Gueliz-Université Cadi Ayyad [Marrakech] (UCA), Laboratoire de Physique de la Matière Condensée - UR UPJV 2081 (LPMC), Université de Picardie Jules Verne (UPJV), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Faculty of Physics, Southern Federal University [Rostov-on-Don] (SFEDU), Institut Josef Stefan, The authors gratefully acknowledge the generous financial support of CNRST Priority Program PPR 15/2015 and the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 778072. Z. K. and B. R. acknowledge Slovenian Research Agency grant J1-9147 and program P1-0125., and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, FOS: Physical sciences, 02 engineering and technology, Dielectric, 01 natural sciences, 7. Clean energy, Hydrothermal circulation, Tetragonal crystal system, 0103 physical sciences, Ceramic, Electrical and Electronic Engineering, Composite material, Perovskite (structure), 010302 applied physics, Condensed Matter - Materials Science, Materials Science (cond-mat.mtrl-sci), [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Ferroelectricity, Atomic and Molecular Physics, and Optics, Grain size, Electronic, Optical and Magnetic Materials, visual_art, visual_art.visual_art_medium, Orthorhombic crystal system, 0210 nano-technology
Abstract: International audience; Lead-free Ba0.85Ca0.15Zr0.10Ti0.90O3 (BCZT) ceramics have demonstrated excellent dielectric, ferroelectric, and piezoelectric properties in comparison to lead-based materials. The synthesis of pure and crystalline BCZT nanopowders at low temperatures of 25, 80, and 160 °C was reported previously by using a sol–gel method followed by a hydrothermal route. In this study, the structural, dielectric, and ferroelectric properties of sintered BCZT ceramics at 1250 °C/10 h were investigated. XRD measurements revealed the presence of a single perovskite phase at room temperature with the coexistence of the orthorhombic and tetragonal symmetries. The increase of grain size and the ceramic density in BCZT ceramics result in an enhancement of the dielectric and ferroelectric properties of BCZT ceramics. More interestingly, the synthesis temperature of BCZT powders with high dielectric and ferroelectric properties could be decreased to a low temperature of 160 °C, which is about 1200 °C lower when compared with solid-state reaction and 840 °C lower when compared with sol–gel methods. The BCZT ceramics elaborated at 160 °C revealed excellent electrical properties (dielectric constant, dielectric loss, remnant polarization, and maximal polarization of 12,085, 0.017, 8.59 µC/cm2, and 27.21 µC/cm2, respectively) and enhanced energy performances (recovered energy density and energy efficiency of 367.2 mJ/cm3 and 67.2%, respectively). Hence, the use of low-temperature hydrothermal processing can be encouraging for the synthesis of lead-free ceramics with high dielectric and ferroelectric properties.
Published: 2020
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19. Carbon heterogeneities in austenite during Quenching & Partitioning (Q&P) process revealed by in situ High Energy X-Ray Diffraction (HEXRD) experiments

Author: Steve Gaudez, Michel Soler, Frédéric Danoix, Guillaume Geandier, Sébastien Allain, Mohamed Gouné, Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Labex DAMAS, Université de Lorraine (UL), Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), ArcelorMittal Maizières Research SA, ArcelorMittal, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), This work was supported by the National Research Agency (ANR). The synchrotron experiments were realized in December 2016, under the P160 grant at DESY PETRA P-07 in Hamburg, which is fully acknowledged. The authors want to thank Jean-Christophe Hell for his support during the experiments. The authors would like also to thank MATERALIA cluster (Region Grand Est) for their support., ANR-14-CE07-0029,CAP NANO,Partition du carbone dans les phases ferritiques nanostructurées: cinétiques et microstructures(2014), ANR-11-LABX-0008,DAMAS,Design des Alliages Métalliques pour Allègement des Structures(2011), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Université de Rouen Normandie (UNIROUEN), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)
Subjects: Diffraction, Materials science, Analytical chemistry, chemistry.chemical_element, 02 engineering and technology, Atom probe, 01 natural sciences, law.invention, [SPI.MAT]Engineering Sciences [physics]/Materials, law, Phase (matter), partitioning, 0103 physical sciences, General Materials Science, steel, X-Ray diffraction, austenite, 010302 applied physics, Quenching, Austenite, Mechanical Engineering, Metals and Alloys, martensite, 021001 nanoscience & nanotechnology, Condensed Matter Physics, chemistry, Mechanics of Materials, Martensite, X-ray crystallography, 0210 nano-technology, Carbon
Abstract: Based on the evolution of the positions and intensities of the diffraction peaks, high energy X-ray diffraction (HEXRD) is recognized as the ultimate method to follow quantitatively in situ phase transformations in steels. However, the possible asymmetricity of diffraction peaks is seldom considered, and is known to bear information. A procedure for quantifying their skewness is proposed. In the case of a third generation high strength steel obtained by quench and partitioning (Q&P), the skewness is shown to be due to carbon heterogeneities at austenite/martensite interfaces developed at nanoscale, in agreement with prior post mortem atom probe tomography (APT) investigations.
Published: 2020
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20. Enhanced dielectric and electrocaloric properties in lead-free rod-like BCZT ceramics

Author: Soukaina Merselmiz, Mimoun El Marssi, Igor A. Luk'yanchuk, M. Spreitzer, M'barek Amjoud, Damjan Vengust, Zdravko Kutnjak, Daoud Mezzane, Zouhair Hanani, Abdelaadim Danine, Nicolas Stein, Yaovi Gagou, Mohammed Lahcini, Mohamed Gouné, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), IMED-Lab, Université Cadi Ayyad [Marrakech] (UCA), Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), UM6P, Laboratoire de Physique de la Matière Condensée - UR UPJV 2081 (LPMC), Université de Picardie Jules Verne (UPJV), Jozef Stefan Institute [Ljubljana] (IJS), Physics Faculty, Southern Federal University [Rostov-on-Don] (SFEDU), and The authors gratefully acknowledge the generous financial support of CNRST Priority Program (PPR 15/2015), Slovenian Research Agency Program (P1-0125), and European Union’s Horizon 2020 Research and Innovation Program under the Marie Skłdowska-Curie Grant Agreement (No. 778072).
Subjects: Phase boundary, Materials science, Scanning electron microscope, 02 engineering and technology, Dielectric, 01 natural sciences, lcsh:TP785-869, Tetragonal crystal system, 0103 physical sciences, rod-like Ba0.85Ca0.15Zr0.10Ti0.90O3 (BCZT), Ceramic, Composite material, dielectric, Perovskite (structure), 010302 applied physics, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Ferroelectricity, electrocaloric effect, Electronic, Optical and Magnetic Materials, lcsh:Clay industries. Ceramics. Glass, visual_art, Ceramics and Composites, visual_art.visual_art_medium, ferroelectric, Selected area diffraction, 0210 nano-technology, lead-free Ba0.85Ca0.15Zr0.10Ti0.90O3 (BCZT)
Abstract: Ba0.85Ca0.15Zr0.10Ti0.90O3 (BCZT) lead-free ceramics demonstrated excellent dielectric, ferroelectric, and piezoelectric properties at the morphotropic phase boundary (MPB). So far, to study the effect of morphological changes on dielectric and ferroelectric properties in lead-free BCZT ceramics, researchers have mostly focused on the influence of spherical grain shape change. In this study, BCZT ceramics with rod-like grains and aspect ratio of about 10 were synthesized by surfactant-assisted solvothermal route. X-ray diffraction (XRD) and selected area electron diffraction (SAED) performed at room temperature confirm the crystallization of pure perovskite with tetragonal symmetry. Scanning electron microscopy (SEM) image showed that BCZT ceramics have kept the 1D rod-like grains with an average aspect ratio of about 4. Rod-like BCZT ceramics exhibit enhanced dielectric ferroelectric (ɛr = 11,906, tanδ = 0.014, Pr = 6.01 μgC/cm2, and Ec = 2.46 kV/cm), and electrocaloric properties (ΔT = 0.492 K and gZ = 0.289 (K·mm)/kV at 17 kV/cm) with respect to spherical BCZT ceramics. Therefore, rod-like BCZT lead-free ceramics have good potential to be used in solid-state refrigeration technology.
Published: 2020
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21. Reflections on the analysis of interfaces and grain boundaries by atom probe tomography

Author: Frédéric Danoix, Paul A. J. Bagot, Michael P. Moody, Mohamed Gouné, Baptiste Gault, Benjamin M. Jenkins, Zirong Peng, University of Oxford, Groupe de physique des matériaux (GPM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Microstructure Physics and Alloy Design [MPIE Düsseldorf], Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Imperial College London, University of Oxford [Oxford], Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), and Normandie Université (NU)
Subjects: 010302 applied physics, Condensed Matter - Materials Science, Interface (Java), Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, 02 engineering and technology, Atom probe, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Microscopy and Microanalysis, 01 natural sciences, Atomic units, Microanalysis, Engineering physics, law.invention, Characterization (materials science), law, 0103 physical sciences, Grain boundary, 0210 nano-technology, Instrumentation, Nanoscopic scale
Abstract: Interfaces play critical roles in materials and are usually both structurally and compositionally complex microstructural features. The precise characterization of their nature in three-dimensions at the atomic scale is one of the grand challenges for microscopy and microanalysis, as this information is crucial to establish structure–property relationships. Atom probe tomography is well suited to analyzing the chemistry of interfaces at the nanoscale. However, optimizing such microanalysis of interfaces requires great care in the implementation across all aspects of the technique from specimen preparation to data analysis and ultimately the interpretation of this information. This article provides critical perspectives on key aspects pertaining to spatial resolution limits and the issues with the compositional analysis that can limit the quantification of interface measurements. Here, we use the example of grain boundaries in steels; however, the results are applicable for the characterization of grain boundaries and transformation interfaces in a very wide range of industrially relevant engineering materials.
Published: 2020
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22. Microstructure Evolution and Competitive Reactions during Quenching and Partitioning of a Model Fe–C–Mn–Si Alloy

Author: Guillaume Geandier, Samy Aoued, Steve Gaudez, Mohamed Gouné, Frédéric Danoix, Jean-Christophe Hell, Michel Soler, Sébastien Allain, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ArcelorMittal Maizières Research SA, ArcelorMittal, This work was partly carried out owing the experimental GENESIS platform. GENESIS is supported by the region Haute-Normandie, the Metropole Rouen Normandie, the CNRS via LABEX EMC, and the French National Research Agency as part of the program 'Investissement d’Avenir' ANR 11-EQPX-002. The synchrotron experiments were realized in December 2016 under the P160 grant at DESY PETRA P-07 in Hamburg, which is fully acknowledged. The authors would like also to thank MATERALIA cluster (Region Grand Est) for their support., ANR-14-CE07-0029,CAP NANO,Partition du carbone dans les phases ferritiques nanostructurées: cinétiques et microstructures(2014), ANR-11-LABX-0008,DAMAS,Design des Alliages Métalliques pour Allègement des Structures(2011), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Labex DAMAS, Université de Lorraine (UL), and ANR-11-EQPX-0020,GENESIS,Groupe d'Etudes et de Nanoanalyses des Effets d'IrradiationS(2011)
Subjects: lcsh:TN1-997, Materials science, Bainite, Alloy, chemistry.chemical_element, Thermodynamics, 02 engineering and technology, Atom probe, engineering.material, Lath, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, law.invention, [SPI]Engineering Sciences [physics], law, partitioning, 0103 physical sciences, General Materials Science, ddc:530, high-energy X-ray diffraction, lcsh:Mining engineering. Metallurgy, 010302 applied physics, Quenching, Austenite, Metals and Alloys, 021001 nanoscience & nanotechnology, atom probe tomography, chemistry, Martensite, steels, engineering, quenching and partitioning, 0210 nano-technology, Carbon
Abstract: The mechanisms behind the carbon enrichment of austenite during quenching and partitioning are still a matter of debate. This work investigates the microstructural evolution during the quenching and partitioning of a model Fe&ndash, C&ndash, Mn&ndash, Si alloy by means of in situ high energy X-ray diffraction (HEXRD) atom probe tomography, and image analysis. The ultra-fast time-resolved quantitative information about phase transformations coupled with image analysis highlights the formation of carbide-free BCT bainite, which is formed within a very short range during the reheating and partitioning step. Its transformation rate, which is a better indicator than the intrinsic volume fraction, depends on the quenching temperature (QT). It is shown to decrease with decreasing QT, from 45% at QT = 260 &deg, C to 20% at QT = 200 &deg, C. As a consequence, a significant part of the carbon enrichment observed in austenite can be attributed to bainite transformation. Furthermore, a large part of carbon was shown to be trapped into martensite. Both the formation of Fe2.6C iron carbides and the segregation of carbon on lath boundaries in martensite were highlighted by atom probe tomography. The energy for carbon segregation was determined to be 0.20 eV, and the carbon concentration on the lath boundaries was obtained to be around 25 at %. Therefore, the carbon enrichment of austenite is the result of competitive reactions such as carbon partitioning from martensite, bainite transformation, and carbon trapping in martensite.
Published: 2020
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23. Phase transitions, energy storage performances and electrocaloric effect of the lead-free Ba0.85Ca0.15Zr0.10Ti0.90O3 ceramic relaxor

Author: Mimoun El Marssi, Yaovi Gagou, M'barek Amjoud, Daoud Mezzane, Zouhair Hanani, Khalid Hoummada, Anna G. Razumnaya, Sébastien Fourcade, Mohamed Gouné, Laboratoire de Matière Condensée et Nanostructures (LMCN), Faculté des Sciences et Techniques Gueliz-Université Cadi Ayyad [Marrakech] (UCA), Faculty of Physics, Southern Federal University [Rostov-on-Don] (SFEDU), Laboratoire de Physique de la Matière Condensée - UR UPJV 2081 (LPMC), Université de Picardie Jules Verne (UPJV), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), The authors gratefully acknowledge the generous financial support of CNRST Priority Program PPR 15/2015 and the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant Agreement No. 778072., and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010302 applied physics, Phase boundary, Condensed Matter - Materials Science, Materials science, Analytical chemistry, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, Dielectric, [CHIM.MATE]Chemical Sciences/Material chemistry, Condensed Matter Physics, 01 natural sciences, Ferroelectricity, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Tetragonal crystal system, visual_art, 0103 physical sciences, visual_art.visual_art_medium, Electrocaloric effect, Orthorhombic crystal system, Ceramic, Electrical and Electronic Engineering, Perovskite (structure)
Abstract: International audience; Lead-free Ba0.85Ca0.15Zr0.10Ti0.90O3 (BCZT) ceramic exhibits excellent dielectric, ferroelectric and piezoelectric properties at the morphotropic phase boundary (MPB). Previously, we demonstrated that the use of the anionic surfactant sodium dodecyl sulfate (SDS, NaC12H25SO4) could enhance the dielectric properties of BCZT ceramic using surfactant-assisted solvothermal processing [1]. In the present study, structural, dielectric, ferroelectric properties, as well as electrocaloric effect and energy storage performances of this BCZT ceramic were thoroughly investigated. X-ray diffraction (XRD) measurements revealed the presence of single perovskite phase at room temperature with the coexistence of orthorhombic and tetragonal symmetries. In-situ Raman spectroscopy results confirmed the existence of all phase transitions from rhombohedral through orthorhombic and tetragonal to cubic symmetries when the temperature varies as reported in undoped-BaTiO3. Evolution of energy storage performances with temperature have been investigated. BCZT ceramic exhibits a high energy storage efficiency of ~ 80% at 120 °C. In addition, the electrocaloric responsivity was found to be 0.164 × 10−6 K·m/V at 363 K.
Published: 2019
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24. Alloying-element interactions with austenite/martensite interface during quenching and partitioning of a model Fe-C-Mn-Si alloy

Author: Frédéric Danoix, Angeline Poulon-Quintin, Michel Soler, Mohamed Gouné, Jean-Christophe Hell, Guillaume Geandier, Sébastien Allain, Samy Aoued, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ArcelorMittal Maizières Research SA, ArcelorMittal, This work was supported by French National Research Agency through the project CAPNANO., ANR-14-CE07-0029,CAP NANO,Partition du carbone dans les phases ferritiques nanostructurées: cinétiques et microstructures(2014), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Quenching and partitioning, Alloy, chemistry.chemical_element, Thermodynamics, 02 engineering and technology, Manganese, Atom probe, engineering.material, 01 natural sciences, law.invention, X-Ray Diffraction, law, 0103 physical sciences, General Materials Science, 010302 applied physics, Austenite, Quenching, Mechanical Engineering, Metals and Alloys, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Atom probe tomography, chemistry, High Energy, Mechanics of Materials, Martensite, X-ray crystallography, engineering, Steels, 0210 nano-technology, Carbon, Partitioning
Abstract: International audience; The alloying elements partitioning from martensite to austenite during quenching and partitioning was analysed by coupling in situ High Energy X-Ray Diffraction experiments and 3D atom probe tomography. A rapid and significant carbon partitioning from martensite to austenite without any partitioning of both Mn and Si was highlighted while the interface was immobile. After a relatively short time at 400 °C, a clear Mn partitioning occurs at the vicinity of the α′/γ interface. The analysis conducted indicates that manganese equilibrates its chemical potential during partitioning and raises the issue of the Constrained Carbon Equilibrium model applicability throughout the partitioning process.
Published: 2019
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25. Mechanism of Austenite Formation from Spheroidized Microstructure in an Intermediate Fe-0.1C-3.5Mn Steel

Author: Astrid Perlade, Olivier Bouaziz, Yves Bréchet, Mohamed Gouné, Pascal Jacques, Thomas Pardoen, Qingquan Lai, Science et Ingénierie des Matériaux et Procédés (SIMaP ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), University of British Columbia (UBC), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB), ArcelorMittal R&D Automat, ArcelorMittal Maizières Research SA, ArcelorMittal-ArcelorMittal, Institute of Mechanics, Materials and Civil Engineering [Louvain] (IMMC), Université Catholique de Louvain = Catholic University of Louvain (UCL), Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies, and HESAM Université (HESAM)-HESAM Université (HESAM)
Subjects: 010302 applied physics, Austenite, Materials science, Ledeburite, Annealing (metallurgy), Cementite, Bainite, Metallurgy, Alloy, Metals and Alloys, Nucleation, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, engineering.material, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, 01 natural sciences, chemistry.chemical_compound, chemistry, Mechanics of Materials, 0103 physical sciences, engineering, 0210 nano-technology
Abstract: International audience; The austenitization from a spheroidized microstructure during intercritical annealing was studied in a Fe-0.1C-3.5Mn alloy. The austenite grains preferentially nucleate and grow from intergranular cementite. The nucleation at intragranular cementite is significantly retarded or even suppressed. The DICTRA software, assuming local equilibrium conditions, was used to simulate the austenite growth kinetics at various temperatures and for analyzing the austenite growth mechanism. The results indicate that both the mode and the kinetics of austenite growth strongly depend on cementite composition. With sufficiently high cementite Mn content, the austenite growth is essentially composed of two stages, involving the partitioning growth controlled by Mn diffusion inside ferrite, followed by a stage controlled by Mn diffusion within austenite for final equilibration. The partitioning growth results in a homogeneous distribution of carbon within austenite, which is supported by NanoSIMS carbon mapping.
Published: 2016
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26. Influence of martensite volume fraction and hardness on the plastic behavior of dual-phase steels: Experiments and micromechanical modeling

Author: Y. Bréchet, Astrid Perlade, Laurence Brassart, Thomas Pardoen, Mohamed Gouné, Qingquan Lai, Olivier Bouaziz, Marc Verdier, Guillaume Parry, Science et Ingénierie des Matériaux et Procédés (SIMaP ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institute of Mechanics, Materials and Civil Engineering [Louvain] (IMMC), Université Catholique de Louvain = Catholic University of Louvain (UCL), Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB), ArcelorMittal R&D Automat, ArcelorMittal Maizières Research SA, ArcelorMittal-ArcelorMittal, ArcelorMittal Research, and the National Fund for Scientific Research (FNRS, Belgium). The support of BELSPO through IAP 7/21 network.
Subjects: 010302 applied physics, Materials science, Mechanical Engineering, Metallurgy, Micromechanics, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, Plasticity, 021001 nanoscience & nanotechnology, Microstructure, 01 natural sciences, Mechanics of Materials, Martensite, 0103 physical sciences, Ultimate tensile strength, Volume fraction, Hardening (metallurgy), General Materials Science, Elongation, 0210 nano-technology
Abstract: International audience; Model dual-phase microstructures were developed to decouple the effect of martensite volume fraction and martensite hardness on the plastic behavior of dual-phase steels. The martensite volume fraction ranges from 11% to 37%, involving two levels of martensite hardness. The yield strength and tensile strength increase with increasing martensite volume fraction, while the uniform elongation decreases. The martensite hardness has a weak impact on the initial yield strength, but it significantly affects the flow behavior for sufficiently large martensite volume fraction. Increasing the hardness of the martensite leads to higher tensile strength combined with only a limited impact on uniform elongation, resulting in an improved strength/ductility balance. The experimental results are successfully captured using finite element based micromechanical analysis. Among others, periodic cell calculations show very good predictive capabilities of the overall plastic response when the stage-IV hardening of the ferrite is taken into account. Our numerical analysis reveals that an accurate description of the elasto-plastic behavior of the martensite is a key element to rationalize the mechanical behavior of DP steels. This modeling approach provides a framework for designing dual-phase steels with optimized plastic flow properties.
Published: 2016
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27. List of Authors

Author: Éric Andrieu, Isabelle Aubert, Thierry Auger, Quentin Auzoux, Rémi Batisse, Charlotte Becquart, Pierre Bernard, Christine Blanc, Cédric Bosch, Jamaa Bouhattate, Yves Bréchet, Laurent Briottet, Yann Charles, Pierre Combrade, Thierry Couvant, Juan Creus, David Delafosse, Alexis Deschamps, Olivier Devos, Matthieu Dhondt, Christophe Domain, Véronique Doquet, Joël Douin, Cécilie Duhamel, François Dupoiron, Claude Duret-Thual, Mohamed El May, Xavier Feaugas, Marc Fivel, Samuel Forest, Marion Frégonèse, Monique Gaspérini, Mohamed Gouné, Catherine Guerre, Gilbert Hénaff, Jean-Loup Heuzé, Jean Kittel, Sabrina Marcelin, Philippe Marcus, Frantz Martin, Vincent Maurice, Arnaud Metsue, Bernard Normand, Grégory Odemer, Roland Oltra, Abdelali Oudriss, Thierry Palin-Luc, Nathalie Pauze, Nadine Pébère, Michel Perez, Philippe Pilvin, Angéline Poulon-Quintin, Ingrid Proriol-Serre, Élie Protopopoff, Marion Risbet, Fiona Ruel, Nicolas Saintier, Döme Tanguy, Benoît Ter-Ovanessian, Florian Thebault, Ludovic Thuinet, Marie Touzet-Cortina, Vincent Vignal, Aurélien Villani, Vincent Vivier, Jean-Bernard Vogt, Flavien Vucko, and Krzysztof Wolski
Published: 2019
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28. The Basics to Better Understand Couplings in Physical Metallurgy

Author: Eric Andrieu, Yves Bréchet, Angeline Poulon-Quintin, Mohamed Gouné, Alexis Deschamps, Marc Fivel, and Joël Douin
Subjects: Condensed Matter::Materials Science, Materials science, Condensed matter physics, Stack (abstract data type), Pure metals, Physics::Atomic and Molecular Clusters, Structure (category theory), Nucleation, Internal stress, Crystallographic defect, Physical metallurgy
Abstract: Pure metals and most alloys are crystallized, in other words, formed by a regular stack of atoms, and we refer to them as “crystals”. The FCC and HCP structures are compact, which means they are formed by a stack of compact planes. The difference between these two structures lies in the sequence of the stack: ABCABCABC... (Figure 2.1(e)) for the FCC structure and ABABAB...
Published: 2019
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29. Link between microstructure and mechanical behavior of double annealed medium Mn steel

Author: Artem Arlazarov, Mohamed Gouné, Frédéric Kegel, Alain Hazotte, Olivier Bouaziz, ArcelorMittal Maizières Research SA, ArcelorMittal, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), Labex DAMAS, and Université de Lorraine (UL)
Subjects: 010302 applied physics, Materials science, Transformation Induced Plasticity (TRIP), Annealing (metallurgy), Intercritical annealing, Mechanical Engineering, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, 01 natural sciences, Modelling, Medium Mn Steel, Tensile behavior, Mechanics of Materials, 0103 physical sciences, Ultimate tensile strength, Retained Austenite, General Materials Science, Tensile Behavior, Composite material, 0210 nano-technology, Holding time
Abstract: International audience; Double annealing of low carbon medium Mn steel was studied. The second intercritical annealing was done at 650°C within a range of holding time: 3min to 30h. Tensile properties of the steel were measured as a function of holding time and the relation between microstructure and mechanical behavior was analyzed. Furthermore, a model, based on the mixture law combined with the considerations of equivalent increment of work in each microstructural constituent during mechanical loading, was proposed. The individual mechanical behavior of each considered microstructural constituent was described with the approaches existing in the literature. The complete model shows a very good agreement with the experimental stress-strain curves and predicts well the optimum strength-ductility balance after 2h holding.
Published: 2018
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30. Mechanism of porosity formation and influence on mechanical properties in selective laser melting of Ti-6Al-4V parts

Author: Olivier Ferry, Angeline Poulon-Quintin, Matthias De Sousa, Jonathan Stef, A. Redjaïmia, Mohamed Gouné, Jaafar Ghanbaja, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), WeAre-3D Materials, Institut Jean Lamour (IJL), and Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Morphology (linguistics), Additive manufacturing, Mechanical properties, 02 engineering and technology, Scanning strategy, 01 natural sciences, law.invention, Fracture surface, law, 0103 physical sciences, Ultimate tensile strength, lcsh:TA401-492, General Materials Science, Ti 6al 4v, Ti-6Al-4V, Selective laser melting, Composite material, Porosity, 010302 applied physics, Mechanical Engineering, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Laser, Mechanism (engineering), Mechanics of Materials, Fracture (geology), lcsh:Materials of engineering and construction. Mechanics of materials, 0210 nano-technology, X-ray tomography
Abstract: An original approach based on 2D fracture surface and 3D X-ray tomography analysis is proposed in this paper. Its application in selective laser melting of Ti-6Al-4V provides substantive clarifications regarding both mechanisms of porosity formation and their influence on mechanical properties. Unambiguously, a one-to-one relationship between the scanning strategy pattern and the 3D spatial distribution of porosities is highlighted. In an original manner, the 3D location of porosities, their morphology and their orientation are analyzed with respect to the laser spot path. The results show that pores are mainly localized on the overlay zones and support the lack of energy induced by the lower energy at the periphery of the laser spot as the main mechanism of porosity formation. Finally, both tensile properties and crack path are shown to be influenced by the presence and 3D distribution of porosities. Keywords: Additive manufacturing, Selective laser melting, Ti-6Al-4V, Porosity, Mechanical properties, Fracture surface, X-ray tomography, Scanning strategy
Published: 2018
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31. Contribution of Local Analysis Techniques for the Characterization of Iron and Alloying Elements in Nitrides: Consequences on the Precipitation Process in Fe⁻Si and Fe⁻Cr Nitrided Alloys

Author: Hugo P, Van Landeghem, Raphaële, Danoix, Mohamed, Gouné, Sylvie, Bordère, Andrius, Martinavičius, Peter, Jessner, Thierry, Epicier, Béatrice, Hannoyer, Frédéric, Danoix, and Abdelkrim, Redjaïmia
Subjects: clusters precipitation, APT and TEM characterization, excess nitrogen, Fe–Si and Fe–Cr nitrided alloys, Article
Abstract: Atom Probe Tomography (APT), Transmission Electron Microscopy (TEM), and 3D mechanical calculations in complex geometry and anisotropic strain fields were employed to study the role of minor elements in the precipitation process of silicon and chromium nitrides in nitrided Fe–Si and Fe–Cr alloys, respectively. In nitrided Fe–Si alloys, an original sequence of Si3N4 precipitation was highlighted. Al–N clusters form first and act as nucleation sites for amorphous Si3N4 nitrides. This novel example of particle-simulated nucleation opens a new way to control Si3N4 precipitation in Fe–Si alloys. In nitrided Fe–Cr alloys, both the presence of iron in chromium nitrides and excess nitrogen in the ferritic matrix are unquestionably proved. Only a certain part of the so-called excess nitrogen is shown to be explained by the elastic accommodation of the misfit between nitride and the ferritic matrix. The presence of immobile excess nitrogen trapped at interfaces can be highly suspected.
Published: 2018

32. Very-low temperature synthesis of pure and crystalline lead-free Ba.85Ca.15Zr.1Ti.9O3 ceramic

Author: M.’barek Amjoud, Mohamed Gouné, Daoud Mezzane, Zouhair Hanani, Sébastien Fourcade, El-Houssaine Ablouh, Laboratory of Condensed Matter and Nanostructures, Université Cadi Ayyad [Marrakech] (UCA), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratory of Bioorganic and Macromolecular Chemistry, and Funding from the CNRST Priority Program PPR 15/2015 and the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 778072.
Subjects: Morphology (linguistics), Materials science, Growth mechanism, 02 engineering and technology, Dielectric, 01 natural sciences, chemistry.chemical_compound, Crystallinity, 0103 physical sciences, Materials Chemistry, Ceramic, Sol-gel-hydrothermal, 010302 applied physics, Process Chemistry and Technology, Lead-free ceramic, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Microstructure, Ferroelectricity, Piezoelectricity, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Chemical engineering, chemistry, visual_art, Barium titanate, Ceramics and Composites, visual_art.visual_art_medium, 0210 nano-technology, Low-temperature
Abstract: International audience; The site-doping strategy of barium titanate (BaTiO3) is a promising way to develop new lead-free materials for energy with enhanced dielectric and piezoelectric properties. A novel strategy to elaborated pure and crystalline Ba.85Ca.15Zr.1Ti.9O3 (BCZT) ferroelectric powders at low temperature is proposed. It is based on sol-gel method followed by a hydrothermal reaction. The effects of preparation temperature on structure, crystallinity, purity, morphology and particles size distribution of BCZT powders were studied. It was clearly shown that pure and crystalline BCZT could be obtained over 80 °C. Furthermore, the BCZT particles exhibit a spherical shape whose mean size increases from 145 nm at 40 °C to 160 nm at 80 °C. The present study may provide a new strategy to design lead-free ferroelectric materials with enhanced structure and microstructure properties at very low temperature.
Published: 2018
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33. Hydrothermal sintering for densification of silica. Evidence for the role of water

Author: Alain Largeteau, Arnaud Ndayishimiye, Stéphane Mornet, Graziella Goglio, Marie-Anne Dourges, Thomas Hérisson de Beauvoir, Mohamed Gouné, Marc Verdier, Catherine Elissalde, Mathieu Duttine, Dominique Denux, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Science et Ingénierie des Matériaux et Procédés (SIMaP ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Ministère de l’Enseignement Supérieur, de la Recherche et de l’Innovation.
Subjects: Ceramics, Materials science, Condensation polymer, Sintering, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Hydrothermal circulation, Mechanical-chemical effects, Low temperature processing densification, Hydrothermal sintering, Materials Chemistry, Ceramic, Composite material, Porosity, Polycondensation, Macropore, Silica, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, visual_art, Ceramics and Composites, visual_art.visual_art_medium, Deformation (engineering), 0210 nano-technology, Mesoporous material
Abstract: International audience; We present hydrothermal sintering as a smart route to densify ceramics at low temperature. Home-made silica nanoparticles naturally hydrated, partially and quasi-fully dehydrated were submitted to hydrothermal sintering (190 MPa, 300 °C, 90 min) without additional water. Their morphology and surface chemistry strongly influence their packing and then the mechanical-chemical effects responsible for densification involving dissolution-precipitation mechanisms. The connection between the porosity and the starting compact packing was pointed out. Moreover, the influence of additional chemical effects was highlighted as the polycondensation of protruding silanols favors the formation of interparticle necks via the creation of polysiloxane bonds. When external water is added, the filling of the mesopores is nearly fully achieved but large residual macropores initiated in the early stage of sintering are remaining. The compactness of the as-obtained ceramic is 73.6%. We also demonstrate the influence of water on the mechanical and deformation behavior of the samples.
Published: 2018
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34. Carbon diffusivity and kinetics of spinodal decomposition of martensite in a model Fe-Ni-C alloy

Author: Helena Zapolsky, Philippe Maugis, Myriam Dumont, Mohamed Gouné, Sophie Cazottes, Sergiu Curelea, Frédéric Danoix, Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Groupe de physique des matériaux (GPM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ANR-13-BS08-0014,SPIDERMAN,Etude de la décomposition spinodale dans les aciers martensitiques Fe-X-C(2013), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), and Normandie Université (NU)
Subjects: Materials science, Spinodal decomposition, Alloy, Kinetics, Thermodynamics, 02 engineering and technology, Atom probe, engineering.material, Thermal diffusivity, 01 natural sciences, 7. Clean energy, Atomic units, law.invention, law, 0103 physical sciences, General Materials Science, Redistribution (chemistry), Martensite, 010302 applied physics, Mechanical Engineering, Carbon diffusion, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Atom probe tomography, Mechanics of Materials, engineering, Steels, 0210 nano-technology
Abstract: International audience; From direct observations and measurements at the atomic scale by atom probe tomography coupled with calculations using a mean-field approach, the kinetics of low temperature carbon redistribution in martensite of a Fe-Ni-C alloy was investigated for duration up to 4.5 years. The results suggest that the ordered phase α″-Fe16C2 forms via a spinodal decomposition mechanism, in the range of a few days at room-temperature. The approach proposed allows us to retrieve the diffusivity of carbon in a large composition range during decomposition kinetics of martensite into α-Fe and α″-Fe16C2.
Published: 2018
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35. Microstructure refinement of dual-phase steels with 3.5wt% Mn: Influence on plastic and fracture behavior

Author: Astrid Perlade, Mohamed Gouné, Yves Bréchet, Thomas Pardoen, Qingquan Lai, Olivier Bouaziz, Science et Ingénierie des Matériaux et Procédés (SIMaP), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB), ArcelorMittal R&D Automat, ArcelorMittal Maizières Research SA, ArcelorMittal-ArcelorMittal, IMAP, Université Catholique de Louvain = Catholic University of Louvain (UCL), and ArcelorMittal Research
Subjects: Austenite, Materials science, Plasticity, Dual-phase steel, Mechanical Engineering, Metallurgy, 0211 other engineering and technologies, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, Damage, Fracture, Mechanics of Materials, Phase (matter), Ultrafine-grained metals, Fracture (geology), General Materials Science, Elongation, 0210 nano-technology, 021102 mining & metallurgy
Abstract: International audience; The plastic and fracture behavior of ultrafine-grained dual-phase (UFG-DP) steels (Fe-0.1 wt%C-3.5 wt%Mn) were analysed from the comparison with the coarser grained DP microstructures taken as references. The UFG-DP steel exhibits a superior balance between strength, uniform elongation and true fracture strain. The higher mechanical performance is explained by both a size effect and a relatively high Mn content in austenite which lead to a Transformation-Induced-Plasticity effect. Furthermore, the analysis shows that microstructure refinement significantly retards damage accumulation and modifies the dominant damage mechanism and fracture behavior. The analysis confirms that the present grade of ultrafine-grained DP steels is a serious candidate for automotive applications.
Published: 2015
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36. Enhancement of dielectric properties of lead-free BCZT ferroelectric ceramics by grain size engineering

Author: Igor A. Luk'yanchuk, Zouhair Hanani, Anna G. Razumnaya, M'barek Amjoud, Daoud Mezzane, Sébastien Fourcade, Mohamed Gouné, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Matière Condensée et Nanostructures (LMCN), Faculté des Sciences et Techniques Gueliz-Université Cadi Ayyad [Marrakech] (UCA), Laboratoire de Physique de la Matière Condensée - UR UPJV 2081 (LPMC), Université de Picardie Jules Verne (UPJV), Faculty of Physics, Southern Federal University [Rostov-on-Don] (SFEDU), L.D. Landau Institute for Theoretical Physics of RAS, Russian Academy of Sciences [Moscow] (RAS), and The authors gratefully acknowledge the generous financial support of CNRST Priority Program PPR 15/2015 and H2020-MSCA-RISE-2017-ENGIMA action.
Subjects: Materials science, Dielectric, Sintering, FOS: Physical sciences, 02 engineering and technology, Applied Physics (physics.app-ph), 01 natural sciences, Lead-free, Physics - Chemical Physics, 0103 physical sciences, General Materials Science, Ceramic, Electrical and Electronic Engineering, Composite material, Microstructure, 010302 applied physics, Relaxor, Chemical Physics (physics.chem-ph), Ferroelectric ceramics, Physics - Applied Physics, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Ferroelectricity, Grain size, visual_art, BCZT, visual_art.visual_art_medium, Dielectric loss, 0210 nano-technology, Ferroelectric
Abstract: Lead-free Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZT) ceramics had attracted much attention for the fabrication of microelectronic devices by virtue of their excellent dielectric, ferroelectric and piezoelectric properties. To understand the effects of both mean grain size and grain size distribution on the dielectric properties of lead-free Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZT) ferroelectric relaxors, an original method was proposed. It is based on the surfactant-assisted solvothermal processing coupled with low-temperature conventional sintering at 1250 {\deg}C. In this way, three highly dense BCZT with different mean grain size and dissimilar grain size distribution were designed. A significant increase of dielectric properties was obtained by a control of grain size and densification process. The dielectric constants measured were ranged from 5370 to 9646 and the dielectric loss was enhanced by 70%. Surprisingly, it was evidenced that there is unequivocal link between mean grain size with dielectric properties. Indeed, it was found that the presence of high density of refined grains leads to an improvement of dielectric properties due to an enhancement of densification. This work may provide a new strategy to design ferroelectric materials with enhanced properties., Comment: Superlattices and Microstructures 2018
Published: 2018
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37. Internal stresses and carbon enrichment in austenite of Quenching and Partitioning steels from high energy X-ray diffraction experiments

Author: Michel Soler, Steve Gaudez, Sébastien Allain, Frédéric Danoix, Guillaume Geandier, Jean-Christophe Hell, Samy Aoued, Mohamed Gouné, Angeline Poulon-Quintin, Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ArcelorMittal Maizières Research SA, ArcelorMittal, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), The synchrotron experiments were realized in December 2016, under the P160 grant at DESY PETRA P-07 in Hamburg, which is fully acknowledged., ANR-14-CE07-0029,CAP NANO,Partition du carbone dans les phases ferritiques nanostructurées: cinétiques et microstructures(2014), ANR-11-LABX-0008,DAMAS,Design des Alliages Métalliques pour Allègement des Structures(2011), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Bainite, Thermodynamics, 02 engineering and technology, 01 natural sciences, Austenite, Thermal expansion, Synchrotron, Stress (mechanics), 0103 physical sciences, General Materials Science, Martensite, 010302 applied physics, Quenching, Mechanical Engineering, Metallurgy, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, Mechanics of Materials, Diffusionless transformation, Q&P, Steels, 0210 nano-technology, Internal stresses
Abstract: International audience; Quenching and Partitioning (Q&P) process permits to produce innovative microstructures containing large fraction of carbon enriched retained austenite. The present study highlights that austenite undergoes significant internal stresses generated during such thermal cycle. Both mechanical and chemical contributions are likely to affect its stability at room temperature and thus the resulting mechanical properties of the steel. The experiments carried out by High Energy X-Ray Diffraction (HEXRD) show unambiguously that internal stresses in austenite originate from martensitic transformation strain and from additional hydrostatic stresses induced during both reheating to partitioning temperature and final cooling. These eigenstrains are attributed to the difference in Coefficients of Thermal Expansion (CTE) between martensite and austenite and are predicted successfully with a purely elastic mean field approach. In the present study, retained austenite is shown to be in compression at room temperature. As a consequence, this state of stress contributes to stabilize retained austenite against a possible strain induced transformation at room temperature and affects the way to determine the carbon content in austenite.
Published: 2018
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38. Temperature hysteresis of the order-disorder transition in carbon-supersaturated α-Fe

Author: Frédéric Danoix, Philippe Maugis, Helena Zapolsky, Sophie Cazottes, Mohamed Gouné, Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Groupe de physique des matériaux (GPM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ANR-13-BS08-0014,SPIDERMAN,Etude de la décomposition spinodale dans les aciers martensitiques Fe-X-C(2013), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)
Subjects: 010302 applied physics, Supersaturation, Materials science, Linear elasticity, chemistry.chemical_element, Thermodynamics, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Crystallographic defect, Molecular dynamics, Hysteresis, Order (biology), chemistry, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology, Carbon, Solid solution
Abstract: International audience; Although many works have been devoted to the order-disorder transition in carbon-supersaturated α-Fe, all seem to have overlooked the temperature hysteresis phenomenon occurring around the critical temperature. It is shown, from a mean-field model based on the elasticity theory of point defects, that the origin of the temperature hysteresis is thermodynamic. As a consequence, both the critical temperature and carbon concentration for the order-disorder transition can be defined upon heating and cooling. The results obtained were successfully compared to molecular dynamics simulations, and are evidence that the transition is of first order and that linear elasticity is the predominant source of the thermodynamics of the Fe-C solid solutions.
Published: 2017
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39. Superledge Model for Interphase Precipitation During Austenite-to-Ferrite Transformation

Author: Meng-Yang Chen, Matthias Militzer, Mohamed Gouné, Yves Bréchet, Jer-Ren Yang, Science et Ingénierie des Matériaux et Procédés (SIMaP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Institut National Polytechnique de Grenoble (INPG), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB), Center for Metallurgical Process Engineering, University of British Columbia (UBC), Department of Materials Science and Engineering, and National Taiwan University [Taiwan] (NTU)
Subjects: Materials structure, Austenite, Precipitation kinetics, Structural material, Materials science, Metallurgy, Metals and Alloys, Nucleation, Ferrite, [CHIM.MATE]Chemical Sciences/Material chemistry, Interface, Condensed Matter Physics, Microstructure, Carbide, Mechanics of Materials, Ferrite (iron), Interphase, Metallic materials
Abstract: International audience; A model for interphase precipitation has been developed based on the ledge mechanism of austenite-to-ferrite transformation. Carbide precipitation is considered on the migrating ferrite/austenite interface as an interaction of transformation and precipitation kinetics. The derived equations describe sheet spacing and particle spacing of interphase-precipitated carbides as well as the overall interface velocity which are related to the nucleation rates of carbides and ferrite ledges, respectively. The microstructure characteristics of interphase precipitation are predicted as a function of transformation temperature and steel composition and replicate trends observed experimentally.
Published: 2014
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40. Interactions between ferrite recrystallization and austenite formation in high-strength steels

Author: Lionel Germain, Mohamed Gouné, Abdelahad Chbihi, Alain Hazotte, David Barbier, Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), ArcelorMittal Maizières Research SA, ArcelorMittal, Labex DAMAS, Université de Lorraine (UL), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and ANR-11-LABX-0008,DAMAS,Design des Alliages Métalliques pour Allègement des Structures(2011)
Subjects: Austenite, Materials science, Bainite, Annealing (metallurgy), Mechanical Engineering, Metallurgy, Thermodynamics, Recrystallization (metallurgy), Recrystallization, Ferrite, [CHIM.MATE]Chemical Sciences/Material chemistry, Microstructure, Mechanics of Materials, Thermal, Dynamic recrystallization, General Materials Science, Anisotropy, Mechanisms interaction, Both experimental, Modeling approaches, Cold-rolled high-strength steels
Abstract: International audience; Using both experimental and modeling approaches, we give some clarifications regarding the mechanisms of interaction between ferrite recrystallization and austenite formation in cold-rolled high-strength steels. Using different thermal paths, we show that ferrite recrystallization and austenite formation can be strongly interdependent. The nature of the interaction (weak or strong) affects significantly the austenite formation and the resulting microstructure. We show that the kinetics of austenite formation depends intrinsically on both heating rates and the extent of ferrite recrystallization. An unexpected behavior of austenite growth was also seen at high heating rates. A possible explanation is presented based on the nature of the local equilibrium at the ferrite-austenite interface. The microstructure is more heterogeneous and anisotropic when both austenite formation and ferrite recrystallization overlap. A mechanism of microstructural formation is proposed, and this is supported by 2D simulations' images.
Published: 2014
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41. Interphase precipitation in vanadium-alloyed steels: Strengthening contribution and morphological variability with austenite to ferrite transformation

Author: Jer-Ren Yang, Marc Verdier, Mei-Yung Chen, Mohamed Gouné, Yves Bréchet, Science et Ingénierie des Matériaux et Procédés (SIMaP), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Department of Materials Science and Engineering, National Taiwan University [Taiwan] (NTU), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB), Science et Ingénierie des Matériaux et Procédés [2007-2015] (SIMaP [2007-2015]), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology [2007-2019] (Grenoble INP [2007-2019])-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Polymers and Plastics, Vanadium, chemistry.chemical_element, 02 engineering and technology, 01 natural sciences, Carbide, 0103 physical sciences, Compounds of carbon, 010302 applied physics, chemistry.chemical_classification, Austenite, Metallurgy, Modeling, Metals and Alloys, Ferrite transformation, [CHIM.MATE]Chemical Sciences/Material chemistry, Nanoindentation, 021001 nanoscience & nanotechnology, Microstructure, Electronic, Optical and Magnetic Materials, chemistry, Ceramics and Composites, Ferrite (magnet), Interphase, Steels, Interphase precipitation, 0210 nano-technology
Abstract: International audience; The evolution of characteristic features of interphase precipitation in steels with progressive of austenite-to-ferrite transformation is analyzed from both experimental and modeling approaches. The model developed describing the time and temperature evolution of sheet spacing and particle spacing shows good agreement with the experimental data. The interactions between the transformation and interphase-precipitated carbides are discussed, and particular attention is paid to the occurrence of fibrous carbides. It is suggested that the ease of interface motion is the main factor controlling its appearance. Finally, the local strengthening in a single ferrite grain containing different precipitation states is analyzed by nanoindentation and compared with the theoretical calculations. The evolution of strengthening induced by interphase precipitation with the microstructural parameters is then discussed..
Published: 2014
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42. Application of interrupted cooling experiments to study the mechanism of bainitic ferrite formation in steels

Author: Annika Borgenstam, Hao Chen, John Ågren, Mohamed Gouné, Sybrand van der Zwaag, Ian Zuazo, Joakim Odqvist, Faculty of Aerospace Engineering [Delft], Delft University of Technology (TU Delft), Royal Institute of Technology [Stockholm] (KTH ), ArcelorMittal Maizières Research SA, ArcelorMittal, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB)
Subjects: Materials science, Polymers and Plastics, Thermodynamics, 02 engineering and technology, Kinetic energy, Austenite, 7. Clean energy, 01 natural sciences, Bainitic ferrite, Isothermal process, Dissipation of gibbs energy, symbols.namesake, Transformation kinetics, Critical point (thermodynamics), Ferrite (iron), Solvent drag, 0103 physical sciences, 010302 applied physics, Metallurgy, Metals and Alloys, Interface migration, [CHIM.MATE]Chemical Sciences/Material chemistry, Dissipation, 021001 nanoscience & nanotechnology, Solute drag, Electronic, Optical and Magnetic Materials, Gibbs free energy, Ceramics and Composites, symbols, 0210 nano-technology
Abstract: International audience; New interrupted cooling experiments have been designed to study the kinetics of bainitic ferrite formation starting from a mixture of austenite and bainitic ferrite. It is found that the kinetics of bainitic ferrite formation during the cooling stage is determined by the isothermal holding time. The formation rate of bainitic ferrite at the beginning of the cooling decreases with increasing prior isothermal holding time. An unexpected stagnant stage during the cooling stage appears when the isothermal holding time increases to a critical point. There are two reasons for the occurrence of the stagnant stage: (i) a solute spike in front of the interface; and (ii) kinetic transition. A so-called Gibbs energy balance approach, in which the dissipation of Gibbs energy due to diffusion inside the interface and interface friction is assumed to be equal to the available chemical driving force, is applied to theoretically explain the stagnant stage. A kinetics transition from a fast growth mode without diffusion of Mn and Si inside the austenite-bainitic ferrite interfaces to a slow growth mode with diffusion inside the interface is predicted. The stagnant stage is caused by the transition to a slow growth mode. The Gibbs energy balance approach describes the experimental observations very well.
Published: 2013
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43. Unexpected low-temperature crystallization of amorphous silicon nitride into α-Si3N4 in a ferritic Fe–Si matrix

Author: A. Redjaïmia, H.P. Van Landeghem, Thierry Epicier, Mohamed Gouné, Labex DAMAS, Université de Lorraine (UL), Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), ArcelorMittal Maizières Research SA, ArcelorMittal, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and ANR-11-LABX-0008,DAMAS,Design des Alliages Métalliques pour Allègement des Structures(2011)
Subjects: Materials science, Annealing (metallurgy), Precipitation, 02 engineering and technology, Nitride, 01 natural sciences, Nitrides, law.invention, law, Iron alloys, 0103 physical sciences, General Materials Science, Crystallization, 010302 applied physics, Hexagonal prism, Precipitation (chemistry), Mechanical Engineering, Metallurgy, Metals and Alloys, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Crystallography, Structural change, Mechanics of Materials, 0210 nano-technology, Amorphous silicon nitride, Nitriding
Abstract: Annealing conditions leading to the crystallization of amorphous silicon nitride occurring upon nitriding of Fe–Si alloys have been found. A brief thermodynamic explanation for the occurrence of this unexpected amorphous-to-crystal transition is given. The crystalline precipitates were found to be α-Si3N4 and follow the orientation relationship given by ( 1 1 ¯ 0 ) α -Fe / / ( 10 1 ¯ 0 ) α - Si 3 N 4 with [ 111 ] α -Fe / / [ 0001 ] α - Si 3 N 4 . This transition happens in precipitates with a constant Si3N4 composition. This structural change also leads to a morphological change from the initial cube-like shape to a hexagonal prism.
Published: 2013
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44. Static and dynamical ageing processes at room temperature in a Fe25Ni0.4C virgin martensite: effect of C redistribution at the nanoscale

Author: Sébastien Allain, Frédéric Danoix, Mohamed Gouné, Khalid Hoummada, Dominique Mangelinck, ArcelorMittal, Groupe de physique des matériaux (GPM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben (MUL), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB), and Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)
Subjects: Materials science, Alloy, 02 engineering and technology, Atom probe, engineering.material, 01 natural sciences, Atomic units, Tensile strength, law.invention, law, 0103 physical sciences, Ultimate tensile strength, Martensite, Redistribution (chemistry), Composite material, 010302 applied physics, Metallurgy, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Carbon, Ageing, Atom probe tomography, Steel, engineering, 0210 nano-technology, Solid solution
Abstract: International audience; The work-hardening behaviour of virgin martensitic steel has been investigated in a strictly un-aged state and after various ageing conditions. At room temperature (RT), the un-aged alloy shows astonishing tensile performances (ultimate tensile stress = 1600 MPa/uniform elongation = 15%) but unexpected serrations. These serrations can be suppressed by static ageing (at RT or higher) while maintaining the initial work-hardening rate (ageing at RT). Parallel investigations using atom probe tomography reveal that the distribution of carbon at the atomic scale evolves from purely homogeneous for virgin martensite to partly segregated at a very fine scale (5-10 nm) after static ageing. This particular mechanical behaviour can therefore be associated with a very local decrease in available carbon in solid solution due to redistribution and segregations on defects (nanotwins) that occurs rapidly, even after few days at RT.
Published: 2013
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45. Mechanism of Si3N4 precipitation in nitrided Fe-Si alloys: A novel example of particle-stimulated-nucleation

Author: A. Redjaïmia, Raphaële Danoix, H.P. Van Landeghem, Frédéric Danoix, Mohamed Gouné, A. Martinavičius, Labex DAMAS, Université de Lorraine (UL), Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB), ANR-11-LABX-0008,DAMAS,Design des Alliages Métalliques pour Allègement des Structures(2011), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Silicon nitride, Nitriding Steel, Materials science, Silicon, Annealing (metallurgy), Alloy, Nucleation, chemistry.chemical_element, 02 engineering and technology, Atom probe, Precipitation, Nitride, engineering.material, law.invention, chemistry.chemical_compound, law, General Materials Science, 020502 materials, Mechanical Engineering, Metallurgy, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Atom probe tomography, 0205 materials engineering, chemistry, Chemical engineering, Mechanics of Materials, engineering, 0210 nano-technology, Nitriding
Abstract: International audience; Atom probe tomography (APT) was employed to investigate the precipitation process of Si3N4 particles after plasma assisted nitriding and subsequent annealing of Fe-Si alloy. The nitriding was done using 15N2 medium to enable quantitative analysis of Si and N by APT. Al, as a minor alloying element, is found to play an important role in the precipitation sequence. It is shown that Al forms Al-N clusters before Si3N4 precipitation takes place, and provides nucleation sites for the precipitation of Si3N4. Composition measurements show that silicon nitrides are enriched in Al, Ti and Mn as compared to the matrix.
Published: 2017
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46. Effects of Q&P processing conditions on austenite carbon enrichment studied by in situ high-energy x-ray diffraction experiments

Author: Mohamed Gouné, Michel Soler, Sébastien Allain, Guillaume Geandier, Frédéric Danoix, Jean-Christophe Hell, Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), ArcelorMittal Maizières Research SA, ArcelorMittal, Groupe de physique des matériaux (GPM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), The synchrotron experiments were realized in December 2014, under the MA2305 grant at the ESRF in Grenoble, which is fully acknowledged. The authors would like also to thank MATERIALIA cluster from Lorraine for their support., ANR-14-CE07-0029,CAP NANO,Partition du carbone dans les phases ferritiques nanostructurées: cinétiques et microstructures(2014), ANR-11-LABX-0008,DAMAS,Design des Alliages Métalliques pour Allègement des Structures(2011), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB)
Subjects: lcsh:TN1-997, HEXRD, Materials science, Bainite, steel, martensite, bainite, Q&P; synchrotron, TRIP, Diffusion, Thermodynamics, chemistry.chemical_element, 02 engineering and technology, 01 natural sciences, Isothermal process, 0103 physical sciences, synchrotron, General Materials Science, lcsh:Mining engineering. Metallurgy, 010302 applied physics, Austenite, Quenching, Metallurgy, Metals and Alloys, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Microstructure, Q&amp, chemistry, Martensite, Q&P, 0210 nano-technology, Carbon
Abstract: International audience; We report the first ultra-fast time-resolved quantitative information on the quenching and partitioning process of conventional high-strength steel by an in situ high-energy X-ray diffraction (HEXRD) experiment. The time and temperature evolutions of phase fractions, their carbon content, and internal stresses were determined and discussed for different process parameters. It is shown that the austenite-to-martensite transformation below the martensite start temperature Ms is followed by a stage of fast carbon enrichment in austenite during isothermal holding at both 400 and 450 °C. The analysis proposed supports the concurrent bainite transformation and carbon diffusion from martensite to austenite as the main mechanisms of this enrichment. Furthermore, we give evidence that high hydrostatic tensile stresses in austenite are produced during the final quenching, and must be taken into account for the estimation of the carbon content in austenite. Finally, a large amount of carbon is shown to be trapped in the microstructure.
Published: 2017
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47. The Mechanisms of Transformation and Mechanical Behavior of Ferrous Martensite

Author: Frédéric Danoix, Sébastien Allain, Chad W. Sinclair, Mohamed Gouné, Guillaume Badinier, University of British Columbia (UBC), Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Groupe de physique des matériaux (GPM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB)
Subjects: Materials science, Yield strength, Metallurgy, Work hardening, Mechanical properties, 02 engineering and technology, Precipitation, 021001 nanoscience & nanotechnology, Microstructure, 020501 mining & metallurgy, Characterization (materials science), Martensitic microstructure, [SPI.MAT]Engineering Sciences [physics]/Materials, Diffusion, Fracture, 0205 materials engineering, Martensite, Phase transformations, Steels, Carbides, 0210 nano-technology
Abstract: International audience; Martensitic steels are among the most important structural materials used today, yet they are far from being completely understood. In this article we survey the academic literature pertaining to ferrous martensite, from seminal works performed starting in the mid 20th century to the insight gained from the availability of modern characterization technology within the last several years. The mechanisms governing the formation of the martensitic microstructure and its dependence on chemistry and processing route are critically evaluated. This is followed by a description of our current understanding of the relationship between microstructure and mechanical properties, particularly yield strength and work hardening rate. Throughout, we aim to highlight topics that remain open as unanswered areas for continued research.
Published: 2017
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48. In-situ investigation of quenching and partitioning by High Energy X-Ray Diffraction experiments

Author: Guillaume Geandier, Frédéric Danoix, Sébastien Allain, Jean-Christophe Hell, Michel Soler, Mohamed Gouné, Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), ArcelorMittal Maizières Research SA, ArcelorMittal, Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB), The synchrotron experiments have been realized in December 2014 under the MA2305 grant at the ESRF in Grenoble which is fully acknowledged. The authors would like also to thank MATERIALIA cluster and the LABEX DAMAS (ANR-11-LABX-0008-01) from Lorraine for their supports., ANR-14-CE07-0029,CAP NANO,Partition du carbone dans les phases ferritiques nanostructurées: cinétiques et microstructures(2014), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Diffraction, Materials science, Quenching and partitioning, Diffusion, Analytical chemistry, chemistry.chemical_element, 02 engineering and technology, In-situ High Energy X-Ray Diffraction, 01 natural sciences, Phase (matter), 0103 physical sciences, General Materials Science, 010302 applied physics, Austenite, Quenching, Mechanical Engineering, Metallurgy, Metals and Alloys, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Phase transformation, chemistry, Mechanics of Materials, Martensite, X-ray crystallography, Steels, 0210 nano-technology, Carbon, Partitioning
Abstract: International audience; We report the first ultra-fast time-resolved quantitative information on the quenching and partitioning process of conventional high strength steel by in-situ High Energy X-Ray Diffraction experiment. The time and temperature evolutions of phase fractions, their carbon content and internal stresses were determined. The austenite to martensite transformation below Ms is followed by a stagnant stage during which microstructural state remained unchanged. Afterwards, a fast kinetics of carbon enrichment of austenite during the partitioning step at 400 °C is highlighted. The analysis proposed supports the carbon diffusion from martensite to austenite as the main mechanisms responsible for this enrichment.
Published: 2017
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49. Critical factors governing the thermal stability of austenite in an ultra-fined grained medium-Mn steel

Author: Artem Arlazarov, Alain Hazotte, Olivier Bouaziz, Mohamed Gouné, Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), ArcelorMittal Maizières Research SA, ArcelorMittal, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB)
Subjects: retained austenite, 010302 applied physics, Austenite, Materials science, Bainite, Ms temperature, Metallurgy, Critical factors, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, stability, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Grain size, Martensite, Medium-Mn steels, 0103 physical sciences, Thermal stability, 0210 nano-technology
Abstract: International audience; The time-evolution of retained austenite at 650 °C is shown to be a fair indicator of the factors governing the austenite stability. The grain size contribution to austenite stability is evidenced and a martensite start temperature (Ms) law applicable to medium-Mn steels and including both the chemical and size effects is determined.
Published: 2017
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50. Characterization and Modeling of Manganese Effect on Strength and Strain Hardening of Martensitic Carbon Steels

Author: Olivier Bouaziz, Artem Arlazarov, Alain Hazotte, Sébastien Allain, Mohamed Gouné, Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), ArcelorMittal Maizières Research SA, ArcelorMittal, Centre des Matériaux (MAT), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), and Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Composite number, chemistry.chemical_element, 02 engineering and technology, Manganese, 01 natural sciences, medium Mn, 0103 physical sciences, Materials Chemistry, 010302 applied physics, carbon, Mechanical Engineering, Metallurgy, Metals and Alloys, modeling, martensite, [CHIM.MATE]Chemical Sciences/Material chemistry, Strain hardening exponent, 021001 nanoscience & nanotechnology, Characterization (materials science), chemistry, Mechanics of Materials, Martensite, strain-hardening, 0210 nano-technology, Carbon
Abstract: International audience; Carbon and manganese combined effect on the mechanical behavior of martensite was characterized and analyzed using literature and new experimental data of various carbon-manganese steels. A synergy effect of carbon and manganese on the martenstite strength and strain hardening was detected and was then taken into account in a specific way in the simplified model, based on a Continuous Composite Approach. Model was adjusted with only one fitting parameter and the obtained results are in good agreement with experimental stress-strain curves.
Published: 2013
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