55 results on '"Olivier Dezellus"'
Search Results
2. Low temperature study of phase equilibria in the Co–Ni–W ternary system: Evidence of a new intermetallic phase Co3W-D0a
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Jérôme Andrieux, Rafael Cury, Olivier Dezellus, Nicolas Bouliez, Rodica Chiriac, Sophie Cazottes, B. Gardiola, Florence Robaut, Jean-Claude Crivello, François Toche, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie et des Matériaux Paris-Est (ICMPE), Institut de Chimie du CNRS (INC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), 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), Science et Ingénierie des Matériaux et Procédés (SIMaP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)
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010302 applied physics ,Materials science ,Ternary numeral system ,Mechanical Engineering ,Metals and Alloys ,Intermetallic ,Thermodynamics ,Sintering ,chemistry.chemical_element ,02 engineering and technology ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Tungsten ,021001 nanoscience & nanotechnology ,01 natural sciences ,Isothermal process ,chemistry ,Mechanics of Materials ,Phase (matter) ,Powder metallurgy ,0103 physical sciences ,Materials Chemistry ,0210 nano-technology ,Ternary operation ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience; Tungsten heavy alloys (Co-Ni-W) of different compositions were prepared by powder metallurgy (solid sintering), heat treated at 800°C and 1000°C and subsequently analyzed. The experimental phase identifications and composition measurements emphasized discrepancies compared to the isothermal ternary sections simulated with commercial thermodynamic databases. The isothermal sections at 800°C and 1000°C were found more complex than expected since a new intermetallic phase appeared to be stable (D0a structure-Cu3Ti prototype). Likewise, an interpretation of phase equilibria evolution with temperature was established to reach agreement with high temperature data. Formation enthalpies associated with the new phase were obtained through first-principles calculations and supported experimental results as they confirmed the stabilizing role of Ni addition for the D0a structure.
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- 2022
3. Solid State Chemical Interaction Between Ti and Al-Si Alloys
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Olivier Dezellus, B. Gardiola, Sabine Lay, J.C. Viala, M. Zhe, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Science et Ingénierie des Matériaux et Procédés (SIMaP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)
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010302 applied physics ,Microprobe ,Materials science ,Diffusion ,Alloy ,Kinetics ,Metals and Alloys ,02 engineering and technology ,[CHIM.MATE]Chemical Sciences/Material chemistry ,engineering.material ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Chemical physics ,Transmission electron microscopy ,Phase (matter) ,0103 physical sciences ,Materials Chemistry ,engineering ,0210 nano-technology ,Material properties ,Layer (electronics) ,ComputingMilieux_MISCELLANEOUS - Abstract
Diffusion couples of Ti and biphasic alloy Al-7wt%Si were produced and heat-treated at 535 °C for between 1 and 200 hours. The nature and thickness of the phases present in the reaction layer sequence were characterized using conventional techniques such as microprobe analysis and transmission electron microscopy. For short interaction times the interfacial reaction layer consists mainly of silicides, whereas aluminides are formed after times longer than 40h. This variation in the spatial reaction layer sequence over time is explained by the biphasic nature of one of the diffusion couple end-members, with high activity for both elements, and by the huge difference between the composition of the first phase formed at the initial interface and the average composition of the biphasic end-member. This situation, which can be observed in other systems, illustrates the difficulty of confirming that a true diffusion path has been attained in a diffusion couple. Most of the criteria that were first proposed by Kirkaldy and Brown, can apparently be fulfilled, but the system could continue shifting over time towards a more stable configuration. In some systems, as in the case of Al-Si-Ti, the slow kinetics can be problematic, making it impossible to predict a radical change in material properties.
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- 2021
4. A novel experimental method for investigating secondary wetting
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Camille Noûs, Olivier Dezellus, Bruno Jacques, Jacques Lacaze, Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)
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010302 applied physics ,wetting ,Materials science ,0211 other engineering and technologies ,Metals and Alloys ,02 engineering and technology ,[CHIM.MATE]Chemical Sciences/Material chemistry ,01 natural sciences ,secondary wetting ,Industrial and Manufacturing Engineering ,Chemical physics ,Simple (abstract algebra) ,aluminium alloys ,0103 physical sciences ,Wetting ,Bimetallic strip ,021102 mining & metallurgy - Abstract
International audience; This paper proposes a novel and simple technique to study secondary wetting for bimetallic systems characterized by almost perfect primary wetting. The main principle is to promote complete dissociation between primary and secondary wettings, avoiding use of the conventional sessile drop technique and its variants. For the first time, evidence is thus obtained that secondary wetting occurs in aluminium alloys.
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- 2021
5. Investigation of the thermodynamic properties of Al4C3: A combined DFT and DSC study
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G. Mikaelian, Olivier Dezellus, Alain Pasturel, P. Benigni, Alexander Pisch, G. Deffrennes, Science et Ingénierie des Matériaux et Procédés (SIMaP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-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), and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
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Materials science ,General Computer Science ,General Physics and Astronomy ,Thermodynamics ,SCAN+vdW functional 25 ,02 engineering and technology ,Aluminum Carbide ,010402 general chemistry ,01 natural sciences ,Measure (mathematics) ,Heat capacity ,Stability (probability) ,DFT ,Thermodynamic properties ,Differential scanning calorimetry ,General Materials Science ,Experimental data ,General Chemistry ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Standard enthalpy of formation ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,Computational Mathematics ,Mechanics of Materials ,Harmonic ,Density functional theory ,0210 nano-technology - Abstract
International audience; The question of material stability through the determination of the thermodynamic properties is of fundamental and technological importance to any analysis of system properties in many applications. For Al 4 C 3 , its experimental heat of formation varies widely, from −0.187 to −0.363 eV/atom, which makes it difficult to use such experimental information for any reactivity assessment. Here, we demonstrate that density functional theory (DFT), with the recently developed strongly constrained and appropriately normed (SCAN) functional, is especially powerful in critically assessing these experimental data. In order to have a more complete description of thermodynamic properties of Al 4 C 3 , we also determine the temperature dependence of its heat capacity using both the harmonic and quasi-harmonic approximation. In addition, and to select the most efficient approximation , we come back to the experimental background by using differential scanning calorimetry (DSC) to measure this quantity at constant pressure up to high temperatures, namely 873 K.
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- 2020
6. High-temperature-reactivity of Al–Ti alloys in contact with SiC
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Rodica Chiriac, F. Toche, Fabrizio Valenza, Sofia Gambaro, Olivier Dezellus, Gabriele Cacciamani, Maria Luigia Muolo, Alberto Passerone, Institute of Condensed Matter Chemistry and Technologies for Energy (ICMATE), Consiglio Nazionale delle Ricerche (CNR), Department of Chemistry and Industrial Chemistry, Genova University, Universita degli studi di Genova, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
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Work (thermodynamics) ,Materials science ,Wetting ,02 engineering and technology ,Silicon carbide ,Interfacial reactivity ,010402 general chemistry ,01 natural sciences ,Chemical reaction ,[SPI.MAT]Engineering Sciences [physics]/Materials ,Materials Chemistry ,Brazing ,Coupling (piping) ,Microelectronics ,[CHIM]Chemical Sciences ,Composite material ,CALPHAD ,business.industry ,Mechanical Engineering ,Metals and Alloys ,Interfacial reactivity CALPHAD MAX-phase Silicon carbide Al–Ti alloys Wetting ,Al-Ti alloys ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Microstructure ,0104 chemical sciences ,Mechanics of Materials ,MAX-phase ,0210 nano-technology ,business - Abstract
International audience; Several industrial processes involving SiC coupling to Al-Ti alloys (e.g. metallization of SiC components, brazing of SiC parts) require an in-depth knowledge of Al-Ti/SiC interactions occurring at high temperatures. To this end, the surface reactivity between SiC and Al-Ti alloys (Al3Ti and (Al+Al3Ti) systems) was analyzed by specific experiments (wetting, DSC, microstructural examinations) as well as by a thermodynamic approach (CALPHAD method). An Al-C-Si-Ti thermodynamic database was successfully established to calculate several sections and projections in order to compare the computed, expected solid phases formed at the interface with those characterized in wetting experiments. In this way, the change in liquid and solid phases was interpreted and discussed, defining the Ti3(Al,Si)C2 mixed MAX-phase as the main interfacial product created by thechemical reaction, as a function of temperature and alloy composition. This work constitutes a guide for the choice of operating parameters in processes such as brazing or SiC metallization in microelectronic applications, in which the control of interfacial products is one of the most delicate production steps. The approach proposed to monitor the pathway of liquid composition with time and temperature during liquid/solid interaction, successfully applied to interpret the microstructure obtained in wetting experiments, is a promising method for interpreting more complex cases such as homogeneous or even heterogeneous brazing processes.
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- 2019
7. Synthesis, crystallographic structure and thermodynamic properties of T2-Al2MgC2
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Georges Mikaelian, B. Gardiola, Olivier Dezellus, Jérôme Andrieux, Guillaume Deffrennes, Alain Pasturel, Alexander Pisch, P Benigni, Erwann Jeanneau, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon, 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), 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 Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
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Electronic structure ,Materials science ,T2-Al2MgC2 ,Thermodynamics ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,01 natural sciences ,Heat capacity ,Inorganic Chemistry ,Crystal ,Thermodynamic properties ,Materials Chemistry ,Physical and Theoretical Chemistry ,Electronic band structure ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Standard enthalpy of formation ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Density Functional Theory (DFT) ,Al-C-Mg ,Ceramics and Composites ,Phonons ,Direct and indirect band gaps ,0210 nano-technology ,Electronic density - Abstract
T2-Al2MgC2 was synthesized from the elements in a Mg-Al melt at 1000 °C using sealed Ta crucibles. Single crystals of T2-Al2MgC2 were extracted by evaporating the Mg-Al matrix. The crystal structure of T2-Al2MgC2 was refined for the first time on the basis of single-crystal X-ray diffraction. The crystal is trigonal (space group P-3m1, Z = 1) with lattice parameters of a = 3.3767(11) A, c = 5.807(2) A and V = 57.34(5) A3. Based on the refined crystal structure, DFT calculations were conducted to evaluate the thermodynamic properties and the electronic structure of the phase. The heat of formation of T2-Al2MgC2 was calculated to be −23.6 kJ/mol of atoms at 298 K. The heat capacity of T2-Al2MgC2 was measured by DSC from 300 to 871 K and calculated by DFT from 0 to 1000 K. Based on the calculated heat capacity, the entropy of formation of the phase at 298 K was determined to be 70.0 J/mol/K. The band structure and the electronic density of state of T2-Al2MgC2 was calculated leading to an indirect band gap value of 1.73 eV.
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- 2019
8. Critical assessment and thermodynamic modeling of the Al–C system
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Olivier Dezellus, Didier Chaussende, Jérôme Andrieux, B. Gardiola, G. Deffrennes, M. Allam, Alexander Pisch, Rainer Schmid-Fetzer, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-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 Clausthal University of Technology (TU Clausthal)
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010302 applied physics ,Materials science ,General Chemical Engineering ,0211 other engineering and technologies ,Extrapolation ,Binary number ,Thermodynamics ,02 engineering and technology ,General Chemistry ,[CHIM.MATE]Chemical Sciences/Material chemistry ,[CHIM.INOR]Chemical Sciences/Inorganic chemistry ,01 natural sciences ,Standard enthalpy of formation ,Computer Science Applications ,Phase (matter) ,0103 physical sciences ,Multicomponent systems ,Critical assessment ,Binary system ,Thermal analysis ,021102 mining & metallurgy - Abstract
International audience; The Al–C system is the backbone of wide variety of applications in multicomponent systems, and was therefore studied intensively. Yet, considerable disagreements remain in the reported data, and the phase equilibria in the binary system as well as the standard enthalpy of formation of Al4C3 are still debated. In order to establish a reliable thermodynamic description of the Al–C system a thorough and critical assessment of the literature was conducted. The data on the solubility of carbon in liquid Al and on the thermodynamic properties of Al4C3 were assessed, and the peritectic decomposition temperature of Al4C3 was confirmed at 2425 ± 15 K by thermal analysis. Thermodynamic modeling of the Al–C system is provided and compared to previous works. The proposed description was found to be more robust and to carry more physical meaning than any previous modeling of the system, which imply an easier extrapolation of the binary into higher-order systems.
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- 2019
9. A Study on the Temperature of Ohmic Contact to p-Type SiC Based on Ti3SiC2Phase
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Tony Abi-Tannous, Dominique Planson, Olivier Dezellus, Maher Soueidan, Jean-Francois Barbot, Gabriel Ferro, Christophe Raynaud, Marie-France Beaufort, Bérangère Toury, M. Lazar, Ampère, Département Energie Electrique (EE), Ampère (AMPERE), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), 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 National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Pprime (PPRIME), and Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)
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Materials science ,Annealing (metallurgy) ,Analytical chemistry ,02 engineering and technology ,01 natural sciences ,chemistry.chemical_compound ,silicon carbide ,0103 physical sciences ,Silicon carbide ,Ti3SiC2 ,Electrical and Electronic Engineering ,Thin film ,Ti-Al alloy ,Ohmic contact ,010302 applied physics ,Metallurgy ,Contact resistance ,Sputter deposition ,021001 nanoscience & nanotechnology ,Microstructure ,[SPI.TRON]Engineering Sciences [physics]/Electronics ,Electronic, Optical and Magnetic Materials ,chemistry ,Transmission electron microscopy ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,0210 nano-technology - Abstract
International audience; In this paper, the electrical properties of Ti3SiC2-based ohmic contacts formed on p-type 4H-SiC were studied. The growth of Ti3SiC2 thin films were studied onto 4H-SiC substrates by thermal annealing of Ti-Al layers deposited by magnetron sputtering. In this study, we varied the concentrations of Ti and Al (Ti20Al80, Ti30Al70, Ti50Al50, and Ti), and the annealing temperature from 900 °C to 1200 °C for each concentration. X-ray diffraction and transmission electron microscopy analyzes were performed on the samples to determine the microstructure of the annealed layers and to further investigate the compounds formed after annealing. Using the transfer length method structures, the specific contact resistance (SCR) at room temperature of all contacts was measured. The temperature dependence up to 600 °C of the SCR of the best contacts was studied to understand the current mechanisms at the Ti3SiC2/SiC interface. The experimental results are in agreement with the thermionic field emission theory. With this model, the barrier height of the contact varies between 0.71 and 0.85 eV. Finally, ageing tests showed that Ti3SiC2-based contacts were stable and reliable up to 400 h at 600 °C under Ar.
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- 2016
10. Thermal stability of Al2MgC2 and thermodynamic modeling of the Al–C–Mg system - Application to grain refinement of Mg–Al alloys
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Jérôme Andrieux, M. Lomello-Tafin, G. Deffrennes, Alain Pasturel, Olivier Dezellus, Rainer Schmid-Fetzer, Alexander Pisch, B. Gardiola, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire SYstèmes et Matériaux pour la MEcatronique (SYMME), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), 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 Clausthal University of Technology (TU Clausthal)
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010302 applied physics ,Materials science ,General Chemical Engineering ,Alloy ,0211 other engineering and technologies ,Thermodynamics ,[CHIM.MATE]Chemical Sciences/Material chemistry ,02 engineering and technology ,General Chemistry ,Liquidus ,engineering.material ,01 natural sciences ,Computer Science Applications ,Carbide ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,0103 physical sciences ,engineering ,Thermal stability ,Graphite ,Solubility ,Ternary operation ,CALPHAD ,021102 mining & metallurgy - Abstract
International audience; In the scope of supporting the development of Mg–Al alloys and related materials, an experimental study coupled with a CALPHAD thermodynamic modeling of the Al–C–Mg system was conducted. The peritectic decomposition of Al2MgC2 to form Al4C3, graphite and a liquid phase was measured at 1559 ± 10 K by DTA. In order to model the Mg solubility in Al4C3, DFT calculations were performed on the end-member phases Mg4C3, Al2Mg2C3 and Mg2Al2C3 and it was shown that Mg substitutes on the Al2 crystallographic site of the carbide structure. Based on recent literature data and a revised Al–C binary, a model description of the Al–C–Mg ternary is proposed for the first time. More specifically, it is used to calculate the liquidus projection and the phase formation sequence during Scheil solidification of a 91Mg–9Al wt% alloy inoculated with carbon. This work provides a convincing argument that Al2MgC2 is the nucleant responsible for the grain refinement of Mg–Al alloys inoculated by C.
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- 2019
11. Synthesis of Ti matrix composites reinforced with TiC particles: in situ synchrotron X-ray diffraction and modeling
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Jérôme Andrieux, B. Gardiola, Olivier Dezellus, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
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Solid state reaction ,Materials science ,Thermodynamic equilibrium ,Diffusion ,02 engineering and technology ,01 natural sciences ,Carbide ,[SPI.MAT]Engineering Sciences [physics]/Materials ,Reaction rate ,diffusion) ,Synchrotron diffraction ,Powder metallurgy ,0103 physical sciences ,General Materials Science ,Dissolution ,ComputingMilieux_MISCELLANEOUS ,010302 applied physics ,Theory and modeling (kinetics ,Interface Interdiffusion ,Metal matrix composites (MMCs) ,Mechanical Engineering ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Chemical engineering ,Mechanics of Materials ,transport ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Particle size ,0210 nano-technology ,Stoichiometry - Abstract
The reaction tending toward thermodynamic equilibrium during the synthesis of Ti/TiC MMC prepared by the powder metallurgy route was studied by in situ synchrotron X-ray diffraction. The carbide composition was found to change rapidly from its initial stoichiometric value TiC0.96 toward a substoichiometric value (TiC0.57) corresponding to thermodynamic equilibrium with the C-saturated Ti matrix. The reaction rate is very fast, and the solid-state reaction is almost complete after only a few minutes at 1073 K (800 °C) for the smallest particles, whereas the rate-limiting step remains the particle size. In addition, modeling of the diffusion processes in MMCs, i.e., initial dissolution of particles and their trend toward equilibrium composition, was performed using three particles size classes and the calculations were performed using the ThermoCalc and Dictra package. First, dissolution of the smallest particles (10% of the initial TiC0.96 particles) is expected to be achieved after only 1 s at 800 °C. Second, the change in TiC composition leads to an increase in the total amount of carbide in the composite from 16 to 19 mass%. The consequences on the industrial process of Ti/TiC MMC synthesis have also been considered. A typical industrial heat treatment of a MMC billet, 1 h at 900 °C, was modeled, and the results showing an increase in the total amount of carbide in the composite from 16 to 22 mass% are in rather good agreement with the experimental value (21 mass%). This highlights the potential of thermodynamic and kinetic modeling to help understand and optimize industrial processes for MMC synthesis.
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- 2018
12. Thermodynamics of Phase Formation in Mg–Al–C Alloys Applied to Grain Refinement
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Olivier Dezellus, B. Gardiola, Jérôme Andrieux, Rainer Schmid-Fetzer, M. Lomello, Guillaume Deffrennes, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire SYstèmes et Matériaux pour la MEcatronique (SYMME), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Clausthal University of Technology (TU Clausthal), and The Minerals, Metals and Materials Society
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Work (thermodynamics) ,Materials science ,Vapor pressure ,020502 materials ,Metallurgy ,chemistry.chemical_element ,[CHIM.MATE]Chemical Sciences/Material chemistry ,02 engineering and technology ,Mg-Al alloys ,021001 nanoscience & nanotechnology ,Decomposition ,Carbide ,Al2MgC2 ,0205 materials engineering ,chemistry ,Differential thermal analysis ,Al-C-Mg ,0210 nano-technology ,Ternary operation ,Grain refinement ,Carbon ,ComputingMilieux_MISCELLANEOUS ,Bar (unit) - Abstract
Grain refinement of Mg–Al based alloys is challenging because it is known that Zr, which is extremely effective in many Al-free alloys, cannot be used. The addition of carbon through various routes by using carbon-containing sources is considered as an option. The grain refinement mechanisms are still under debate. The present work is focused on the ternary base system Mg–Al–C, including the potential nucleants Al4C3 and Al2MgC2, presently without consideration of Al2CO. The ternary carbide Al2MgC2 was synthesized and characterized using sealed Ta crucibles. The decomposition of the carbide was measured at 1290 °C by Differential Thermal Analysis under a pressure of 8 bar. Practical difficulties, including high vapor pressure of Mg and high affinity of Mg with oxygen, as well as rapid hydrolysis of the Al2MgC2 carbide have been overcome.
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- 2018
13. Microstructure and mechanical properties of an Al–TiC metal matrix composite obtained by reactive synthesis
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B. Gardiola, Nikhil Karnatak, Olivier Dezellus, Sabine Lay, Olivier Martin, Nassim Samer, Laurent Chaffron, Hiroki Kurita, Jérôme Andrieux, Sophie Gourdet, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Mecachrome, Mecach, Laboratoire des Technologies des Matériaux EXtrêmes (LTMEx), Service des Recherches Métallurgiques Appliquées (SRMA), Département des Matériaux pour le Nucléaire (DMN), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département des Matériaux pour le Nucléaire (DMN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, EADS Innovation Works [Toulouse], EADS - European Aeronautic Defense and Space, 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), and 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)
- Subjects
Materials science ,Metal-matrix composites ,Metal matrix composite ,Composite number ,particle-reinforcement ,Mechanical properties ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Microstructure ,Micrometre ,Mechanics of Materials ,Ultimate tensile strength ,Volume fraction ,Ceramics and Composites ,Graphite ,Microstructures ,Composite material ,ComputingMilieux_MISCELLANEOUS ,Solid solution - Abstract
A metal matrix composite has been obtained by a novel synthesis route, reacting Al 3 Ti and graphite at 1000 °C for about 1 min after ball-milling and compaction. The resulting composite is made of an aluminium matrix reinforced by nanometer sized TiC particles (average diameter 70 nm). The average TiC/Al ratio is 34.6 wt.% (22.3 vol.%). The microstructure consists of an intimate mixture of two domains, an unreinforced domain made of the Al solid solution with a low TiC reinforcement content, and a reinforced domain. This composite exhibits uncommon mechanical properties with regard to previous micrometer sized Al–TiC composites and to its high reinforcement volume fraction, with a Young’s modulus of ∼110 GPa, an ultimate tensile strength of about 500 MPa and a maximum elongation of 6%.
- Published
- 2015
14. Elastic properties, thermal stability, and thermodynamic parameters of MoAlB
- Author
-
Diego Lopez, Miladin Radovic, Olivier Dezellus, B. Gardiola, Sankalp Kota, Matthias T. Agne, Eugenio Zapata-Solvas, Michel W. Barsoum, A.J. Drexel Nanomaterials Institute (Philadelphia, USA), Drexel University, Northwestern University [Evanston], Department of Materials, Imperial College London, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Texas A&M University [College Station]
- Subjects
010302 applied physics ,Materials science ,Argon ,02 Physical Sciences ,Scanning electron microscope ,Fluids & Plasmas ,chemistry.chemical_element ,Thermodynamics ,02 engineering and technology ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Atmospheric temperature range ,021001 nanoscience & nanotechnology ,7. Clean energy ,01 natural sciences ,Standard enthalpy of formation ,chemistry.chemical_compound ,Thermal conductivity ,chemistry ,Boride ,Differential thermal analysis ,0103 physical sciences ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Thermal stability ,0210 nano-technology ,03 Chemical Sciences - Abstract
International audience; MoAlB is the first and, so far, the only transition-metal boride that forms alumina when heated in air and is thus potentially useful for high-temperature applications. Herein, the thermal stability in argon and vacuum atmospheres and the thermodynamic parameters of bulk polycrystalline MoAlB were investigated experimentally. At temperatures above 1708 K, in vacuum and inert atmospheres, this compound incongruently melts into the binary MoB and liquid aluminum metal as confirmed by differential thermal analysis, quenching experiments, x-ray diffraction, and scanning electron microscopy. Making use of that information together with heat-capacity measurements in the 4–1000-K temperature range—successfully modeled as the sum of lattice, electronic, and dilation contributions—the standard enthalpy, entropy, and free energy of formation are computed and reported for the full temperature range. The standard enthalpy of formation of MoAlB at 298 K was found to be −132 ± 3.2 kJ/mol. Lastly, the thermal conductivity values are computed and modeled using a variation of the Slack model in the 300–1600-K temperature range.
- Published
- 2017
15. Synthesis of Ti matrix composites reinforced with TiC particles: thermodynamic equilibrium and change in microstructure
- Author
-
Jean-Claude Viala, Olivier Dezellus, Jérôme Roger, B. Gardiola, Jérôme Andrieux, Laboratoire des Composites Thermostructuraux (LCTS), Université de Bordeaux (UB)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Snecma-SAFRAN group-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ANR, and ANR-09-MAPR-0021,COMETTi,COmportement Mécanique Et Tribologique des composites à matrice Titane(2009)
- Subjects
Ostwald ripening ,Materials science ,Thermodynamic equilibrium ,02 engineering and technology ,Processing ,01 natural sciences ,Titanium carbide ,symbols.namesake ,chemistry.chemical_compound ,0103 physical sciences ,General Materials Science ,Composite material ,Dissolution ,ComputingMilieux_MISCELLANEOUS ,010302 applied physics ,Titanium ,Mechanical Engineering ,Metal matrix composite ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Microstructure ,chemistry ,Mechanics of Materials ,symbols ,0210 nano-technology ,Mass fraction ,Stoichiometry ,Chemical change - Abstract
The evolution of TiC reinforcement during the high-temperature consolidation step of a particulate-reinforced Ti matrix composite has been studied. A four-step scenario has been highlighted starting with the dissolution of the smallest particles to reach C saturation of the Ti matrix, followed by a change in the TiC stoichiometry from the initial TiC0.96 composition to the equilibrium composition (TiC0.57). This change in composition induces an increase in both the total mass fraction of reinforcement and the particle diameter. The diameter increase promotes contact between individual particles in the most reinforced domains and initiates an aggregation phenomenon that is responsible for the observed high growth rate of particles for heat treatment times shorter than 1 h. Finally Ostwald ripening is responsible for the growth of particles for longer heat treatment times.
- Published
- 2017
16. New potential for preparation of performing h-BN coatings via polymer pyrolysis in RTA furnace
- Author
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Bérangère Toury, Stéphane Benayoun, Bernard Beaugiraud, Sheng Yuan, Arnaud Brioude, Olivier Dezellus, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Tribologie et Dynamique des Systèmes (LTDS), École Centrale de Lyon (ECL), and Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Ecole Nationale d'Ingénieurs de Saint Etienne-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Materials science ,Annealing (metallurgy) ,chemistry.chemical_element ,02 engineering and technology ,engineering.material ,010402 general chemistry ,01 natural sciences ,law.invention ,Coating ,chemistry.chemical_compound ,law ,Materials Chemistry ,[CHIM]Chemical Sciences ,Ceramic ,Crystallization ,Composite material ,Rapid thermal annealing ,chemistry.chemical_classification ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Polymer ,Ceramic material ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Boron nitride ,[CHIM.POLY]Chemical Sciences/Polymers ,chemistry ,visual_art ,Ceramics and Composites ,visual_art.visual_art_medium ,engineering ,IR irradiation ,0210 nano-technology ,Pyrolysis ,Titanium - Abstract
International audience; An innovative IR irradiation annealing process is used to increase the crystallization ratio of hexagonal boron nitride (h-BN) coatings on pure titanium pellets. Since the polymer pyrolysis route requires heating the green polymer at high temperature to convert it into a ceramic, the use of IR radiation furnace (compared to a resistive furnace) allows achievement of better crystallized h-BN while the substrate remains at relatively low temperature (
- Published
- 2013
17. 4H-SiC(0001) Surface Faceting during Interaction with Liquid Si
- Author
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Gabriel Ferro, Olivier Dezellus, V. Souliere, Judith Woerle, Davy Carole, Ulrike Grossner, Massimo Camarda, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, Paul Scherrer Institute (PSI), Physics Department (ETHZ), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Roccaforte, Fabrizio, La Via, Francesco, Nipoti, Roberta, Crippa, Danilo, Giannazzo, Filippo, and Saggio, Mario
- Subjects
Surface (mathematics) ,Faceting ,Morphology (linguistics) ,Materials science ,Liquid silicon ,02 engineering and technology ,01 natural sciences ,CVD ,Steps ,Etching (microfabrication) ,0103 physical sciences ,[CHIM.CRIS]Chemical Sciences/Cristallography ,Deposition (phase transition) ,[CHIM]Chemical Sciences ,General Materials Science ,010302 applied physics ,Range (particle radiation) ,Mechanical Engineering ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Atmospheric temperature range ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Crystallography ,Mechanics of Materials ,Chemical physics ,Liquid Silicon ,0210 nano-technology - Abstract
The aim of this study was to find conditions allowing the "natural" formation of a regular and controllable step bunched morphology on a 4H-SiC seed without the need of any SiC deposition. This was performed by melting a bulk piece of Si on a 4°off 4H seed in the temperature range of 1500 - 1600°C, for 15 min. After etching the remaining Si, the 4H surface was found to be successfully highly step bunched with steps very parallel and regular. A mechanism of dissolution-precipitation was proposed, which could occur both on a short (step to step) and long (centre to periphery) range. This process is kinetically limited at low temperature (1500-1550°C) and considered to be close to the equilibrium at 1600°C., Materials Science Forum, 858, ISSN:0255-5476, ISSN:1662-9752, Silicon Carbide and Related Materials 2015, ISBN:978-3-0357-1042-7, ISBN:3-0357-1042-2
- Published
- 2016
18. Modified 4-Point Bending Test for Adhesion Measurement at the Interface of Iron Coated with Aluminum Casting Alloy
- Author
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M. Zhe, G. Parry, J.C. Viala, Olivier Dezellus, Muriel Braccini, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Science et Ingénierie des Matériaux et Procédés (SIMaP), and 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)
- Subjects
Toughness ,6111 aluminium alloy ,Materials science ,Metallurgy ,Alloy ,chemistry.chemical_element ,Fracture mechanics ,[CHIM.MATE]Chemical Sciences/Material chemistry ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,Bending ,engineering.material ,021001 nanoscience & nanotechnology ,Surfaces, Coatings and Films ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Alonizing ,chemistry ,Mechanics of Materials ,Aluminium ,Casting (metalworking) ,Materials Chemistry ,engineering ,0210 nano-technology - Abstract
International audience; In order to reduce the weight in automotive or aeronautic components, aluminum and its alloys are being used more and more. However, their mechanical properties are not as good as those of steel and can sometimes be below the necessary requirement. To overcome this issue, reinforcement of some parts is required. In this case, the mechanical reliability of the interface between the aluminum alloy matrix and its reinforcement has to be insured. This can be done by controlling the process parameters involved in developing a strong metallurgical bond between the two metals. In this work an Fe/Al-7 wt% Si alloy interface was investigated, aimed at linking the chemistry of the reaction layers with the toughness of the bond. First, the chemistry of the interface was characterized after immersion of Fe plates in an aluminum alloy melt. Then, the fracture energy of these assemblies was measured using a modified 4-point bending test for the adhesion measurement. In the case of pure elastic deformation during the loading, an analytical approach based on beam bending theory can be used to quantify the fracture energy. Nevertheless, in bonding between metallic partners, plastic dissipation can be expected. This is why a numerical calculation, based on a cohesive zone mode was proposed. The use of cohesive elements to describe the interface behavior allows for modeling both the threshold of de-cohesion and the progression of damage at each point of the interface. (C) Koninklijke Brill NV, Leiden, 2012
- Published
- 2012
19. Al-Si-Ti Ohmic Contacts on N-Type Gallium Nitride
- Author
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Emmanuel Collard, Olivier Ménard, Olivier Dezellus, J.C. Viala, Arnaud Yvon, Christian Brylinski, Nicolas Thierry-Jebali, Miao Zhe, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), STMicroelectronics [Tours] (ST-TOURS), Laboratoire de Microélectronique de Puissance ( LMP ), Université de Tours (UT), and Université de Tours
- Subjects
Ohmic Contact ,Materials science ,Annealing (metallurgy) ,Gallium nitride ,02 engineering and technology ,01 natural sciences ,Metal ,chemistry.chemical_compound ,Electrical resistivity and conductivity ,0103 physical sciences ,Electronic engineering ,[CHIM]Chemical Sciences ,General Materials Science ,Power semiconductor device ,Power Device ,Ti-Al-Si ,Composite material ,Ohmic contact ,Si element ,010302 applied physics ,Mechanical Engineering ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,chemistry ,Mechanics of Materials ,visual_art ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,visual_art.visual_art_medium ,Gallium Nitride (GaN) ,0210 nano-technology ,Metallic bonding - Abstract
International audience; Ohmic contacts represent a major technological brick for the development of high power devices on Gallium Nitride. Al(200 nm) Ti(70 nm) metallization on n+-GaN, annealed at 650 °C, provides a “Specific Contact Resistivity” (SCR) in the range mid 10-5 Ω.cm², which is low enough for the main switching power applications. However, the Al-Ti metallic compound phases formed during the annealing step result from solid-solid reactions, which may lead to high stress and / or poor cohesion, possibly deleterious to contact reliability. In this work, we have investigated several configurations of Ti-Al-Si based contacts, aiming at favoring liquid-solid reactions and / or Si element diffusion, in order to get better SCR and / or morphology and cohesion of the metallic phase. Surprisingly, only contacts annealed at low temperature (450 °C) provide low contact SCR, comparable to that of Ti-Al only contact, but systematically higher.
- Published
- 2011
20. Wettability of Ti3SiC2 by Ag–Cu and Ag–Cu–Ti melts
- Author
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J.C. Viala, Olivier Dezellus, G. Constantin, An-Ping Li, R. Voytovych, Françoise Bosselet, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Science et Ingénierie des Matériaux et Procédés (SIMaP), and 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)
- Subjects
Silver ,Materials science ,Machinability ,Braze alloy ,Ultra-high vacuum ,02 engineering and technology ,01 natural sciences ,Carbide ,Contact angle ,Sessile drop technique ,0103 physical sciences ,General Materials Science ,Ti3SiC2 ,Composite material ,010302 applied physics ,Mechanical Engineering ,Drop (liquid) ,Reactivity ,Metallurgy ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Mechanics of Materials ,Wettability ,Wetting ,0210 nano-technology ,Ternary operation ,Copper - Abstract
International audience; Recently, the ternary carbide Ti3SiC2 has gained much attention due to its unique characteristics combining the properties of metals and ceramics (i.e., a low density, decent thermal and electrical conductivities, an excellent thermal shock resistance, a good machinability, damage tolerance, low friction and so on). The present study describes an investigation of the wettability in high vacuum of bulk Ti3SiC2 by a classical braze alloy based on the Ag-Cu-Ti system. Two techniques, i.e., the sessile drop and dispensed drop methods, were utilized. The results indicated that spreading kinetics is controlled by deoxidation kinetics of Ti3SiC2 surface under vacuum. The final contact angle on clean Ti3SiC2 is very small (~ 10°), testifying the development of strong, metallic interactions across the liquid-solid interface. The reactivity between the ternary carbide and the liquid phase during isothermal heating at 800°C was also considered.
- Published
- 2009
21. 3C-SiC Islands Formation on 6H-SiC(0001) Substrate from a Liquid Phase
- Author
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Efstathios K. Polychroniadis, Davy Carole, J.C. Viala, Gabriel Ferro, Maher Soueidan, Olivier Dezellus, Ariadne Andreadou, and Olivier Kim-Hak
- Subjects
Materials science ,Precipitation (chemistry) ,Mechanical Engineering ,Nucleation ,chemistry.chemical_element ,Substrate (chemistry) ,Germanium ,Condensed Matter Physics ,Crystallography ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Mechanics of Materials ,Propane ,General Materials Science ,Layer (electronics) ,Carbon ,Dissolution - Abstract
Twin-free 3C-SiC layers were recently obtained by Vapour-Liquid-Solid mechanism on a a-SiC(0001) substrate using Si-Ge melt. The formation of cubic layers is rather unexpected since growth from the melt is known to promote lateral growth and should thus give homoepitaxial layers. The study of the early stage of such growth, after a simple contact between the melt and the substrate (without adding propane), reveals the precipitation of 3C-SiC elongated islands upon the substrate surface. The chemical interactions inside the Ge-Si-C ternary phase diagram suggest an initial dissolution of the SiC seed in contact with a Ge-rich melt (below 1200°C). When the Si content of the melt subsequently increases upon heating, the dissolved carbon atoms precipitate on the seed surface under the form of 3C-SiC islands. When propane is added, these islands enlarge and coalesce to form a complete 3C layer.
- Published
- 2008
22. Phase Equilibria and Reactive Chemical Vapor Deposition (RCVD) of Ti3SiC2
- Author
-
Olivier Dezellus, J.C. Viala, Sylvain Jacques, Françoise Bosselet, M.-P. Berthet, M. Sacerdote-Peronnet, and H. Fakih
- Subjects
Chemistry ,Metals and Alloys ,Thermodynamics ,Quinary ,Substrate (electronics) ,Chemical vapor deposition ,Condensed Matter Physics ,Chemical reaction ,Carbide ,chemistry.chemical_compound ,Phase (matter) ,Materials Chemistry ,Silicon carbide ,Deposition (phase transition) - Abstract
The present article addresses the issue of properly modelling the thermodynamic aspect of chemical reactions proceeding at the solid/gas interface in a multi-component system. Attention is more especially paid to the formation of Ti3SiC2 by reactive chemical vapor deposition (RCVD) on a silicon carbide substrate heated at 1100 °C. A deposition diagram has been calculated by Gibbs free energy minimization in the C-Cl-H-Si-Ti quinary system. It is shown that this deposition diagram can account for experimental results obtained by RCVD only for the short period of time during which the reaction layer is thin and discontinuous. For thick, dense and continuous reaction layers, the deposition diagram is no longer appropriate and reaction-diffusion models developed for solid-state diffusion couples have to be used in place of it.
- Published
- 2008
23. Mechanical testing of titanium/aluminium–silicon interfaces by push-out
- Author
-
Myriam Sacerdote-Peronnet, Jean-Claude Viala, Françoise Bosselet, Lucile Milani, Olivier Dezellus, D. Rouby, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Materials science ,Silicon ,Alloy ,chemistry.chemical_element ,02 engineering and technology ,engineering.material ,01 natural sciences ,Stress (mechanics) ,Push-out ,Aluminium ,0103 physical sciences ,Shear strength ,General Materials Science ,Composite material ,Casting ,Titanium ,010302 applied physics ,Mechanical Engineering ,Metallurgy ,Mechanical Properties Testing ,Aluminium alloys ,Fracture mechanics ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Interface ,021001 nanoscience & nanotechnology ,chemistry ,Mechanics of Materials ,engineering ,0210 nano-technology ,Layer (electronics) - Abstract
International audience; Mechanical properties of Ti/Al-7Si assemblies produced by insert moulding have been studied with a classical push-out test and a variant that is the circular bending test. Special care has been taken for controlling both the reactivity at theTi/Al-7Si interface and the metallurgical health of the Al-7Si matrix. Mechanical tests until complete debonding have been completed with interrupted tests, metallographic characterizations and FEM analysis of elastic stress state. A mean shear strength of the interface of about 120 MPa has been obtained. When the Ti insert is solely fretted in the matrix, without chemical interaction between Ti and the Al-7Si alloy, the mean shear strength is significantly lower (48 MPa). This result clearly shows that chemical interaction at the interface (formation of a thin TiSi layer at the Ti side and a thick Al3Ti(Si) layer at the Al-7Si alloy side) improves the mechanical properties of the assembly. It is also shown that the failure sequence is characterized both by crack propagation from bottom to top and matrix yielding from top to bottom. Actually, interface damaging begins by crack initiation at the specimen bottom face (not at the top face, under the indenter) in a nearly pure mode I solicitation at a radial tensile stress of about 100 MPa.
- Published
- 2008
24. Nucleation of 3C–SiC on 6H–SiC from a liquid phase
- Author
-
François Cauwet, Olivier Kim-Hak, Maher Soueidan, Olivier Dezellus, Florence Robaut, Jean-Claude Viala, J. Dazord, Bilal Nsouli, and Gabriel Ferro
- Subjects
Materials science ,Polymers and Plastics ,Precipitation (chemistry) ,Metals and Alloys ,Nucleation ,Analytical chemistry ,chemistry.chemical_element ,Substrate (electronics) ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Electron diffraction ,Propane ,Ceramics and Composites ,Thin film ,Dissolution ,Carbon - Abstract
The aim of this work is to elucidate the mechanism involved in the 3C–SiC formation during growth by a vapor–liquid–solid mechanism on 6H–SiC substrate. Polytype selection is shown to occur at the first stage of the experiments, before propane injection into the reactor. The contact of the seed with a Si–Ge melt during the initial heating ramp causes the formation of 3C–SiC islands on the seed surface, probably below 1200 °C. The proposed mechanism first involves a partial dissolution of the seed in a Ge-rich liquid which becomes C-supersaturated. Then the Si content of the liquid rapidly increases, which provokes the precipitation of the dissolved carbon in the form of 3C–SiC islands. When growth starts upon propane injection, these islands enlarge and coalesce to form a continuous 3C–SiC layer. If the growth temperature is too high (⩾1550 °C), the initial 3C–SiC islands are dissolved and homoepitaxial layers are obtained.
- Published
- 2007
25. Mechanical testing of steel/aluminium–silicon interfaces by pushout
- Author
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Françoise Bosselet, D. Rouby, J.C. Viala, Olivier Dezellus, M. Sacerdote-Peronnet, and B. Digonnet
- Subjects
Materials science ,Polymers and Plastics ,General Chemical Engineering ,Alloy ,Metallurgy ,Intermetallic ,chemistry.chemical_element ,Pushout ,Fracture mechanics ,engineering.material ,Steel bar ,Biomaterials ,Brittleness ,chemistry ,Aluminium ,visual_art ,Aluminium alloy ,visual_art.visual_art_medium ,engineering - Abstract
The functionality of structural light alloy castings can be improved by inserting into them, upon moulding, local iron base reinforcements. To acquire a better knowledge of such bimetallic assemblies, samples were prepared by immersing a mild steel bar (5 mm in diameter) in aluminium base Al-Si alloy melts held at 730 °C. After melt solidification, the bimetallic samples were cut into 5 mm thick slices and pushout testing was performed on these slices. Characterization of damaging corresponding to different load level before complete debonding allows the determination of the failure mode. Crack initiation occurs at the specimen bottom face in the intermetallic reaction layer, important damage occurs before complete debonding and no brittle failure is observed. The results highlight the necessity of analysing pushout tests with a more integrated approach taking into account shear stress distribution along the interface such as interfacial crack growth.
- Published
- 2007
26. Wetting and reactivity in Ni–Si/C system: experiments versus model predictions
- Author
-
Olivier Dezellus, Nicolas Eustathopoulos, V. Bougiouri, and R. Voytovych
- Subjects
Materials science ,Mechanical Engineering ,Drop (liquid) ,Metallurgy ,Ultra-high vacuum ,Kinetics ,Thermodynamics ,Vitreous state ,Sessile drop technique ,Mechanics of Materials ,Solid mechanics ,General Materials Science ,Wetting ,Dissolution - Abstract
Wetting of vitreous carbon Cv by NiSi alloys is studied in high vacuum using the sessile drop and dispensed drop techniques. The role of reactions between NiSi and Cv (simple dissolution or SiC formation) on wetting, adhesion and mechanical behaviour of the interface is determined and discussed. The experimental results on reactive wetting are compared with the predictions of two different approaches proposed recently in order to explain the thermodynamics and kinetics of this type of wetting.
- Published
- 2007
27. Experimental evidence of copper insertion in a crystallographic structure of Ti 3 SiC 2 MAX phase
- Author
-
Sabine Lay, Olivier Dezellus, Jérôme Andrieux, B. Gardiola, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Science et Ingénierie des Matériaux et Procédés (SIMaP), and 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)
- Subjects
Diffraction ,Materials science ,Mechanical Engineering ,Reactivity ,Metals and Alloys ,Energy-dispersive X-ray spectroscopy ,chemistry.chemical_element ,Transmission electronic microscopy ,Crystal structure ,Chemical interaction ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Condensed Matter Physics ,Copper ,Crystallography ,chemistry ,Mechanics of Materials ,Lattice (order) ,General Materials Science ,MAX phase ,Insertion ,ComputingMilieux_MISCELLANEOUS - Abstract
Chemical interaction of Ti3SiC2 substrate with silver–copper (Ag–Cu) melt is studied after several minutes of contact at 800 °C and 900 °C. Experimental evidence of Cu insertion into the crystallographic structure of Ti3SiC2 is given both by X-ray energy dispersive spectroscopy (composition is about Ti47Cu8Si13C32) and by electronic diffraction patterns obtained by transmission electronic microscopy for single grains. Moreover, the X-ray diffraction pattern shows that insertion of Cu induces a slight increase in the lattice parameters and a modification of peak intensities.
- Published
- 2015
28. The growth of Ti3SiC2 coatings onto SiC by reactive chemical vapor deposition using H2 and TiCl4
- Author
-
Françoise Bosselet, M.-P. Berthet, H. Fakih, J.C. Viala, Olivier Dezellus, and Sylvain Jacques
- Subjects
Materials science ,Solid-state ,Mineralogy ,chemistry.chemical_element ,Surfaces and Interfaces ,General Chemistry ,Chemical vapor deposition ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Atomic diffusion ,Dilution ratio ,Chemical engineering ,chemistry ,Phase (matter) ,Materials Chemistry ,Deposition (phase transition) ,Carbon - Abstract
(SiC/Ti 3 SiC 2 ) n multilayered coatings composed of n layers alternately of continuous SiC and Ti 3 SiC 2 sub-layers were prepared on carbon substrates. The method consists in depositing SiC by classical chemical vapor deposition (CVD) and then producing a new Ti-containing sub-layer from a reaction between SiC and a H 2 /TiCl 4 gaseous mixture by reactive CVD (RCVD), and repeating this sequence n times. In accordance with thermodynamics, this RCVD method produces only pure TiC sub-layers when a low dilution ratio of TiCl 4 in H 2 ( R = [H 2 ]/[TiCl 4 ]) is used. With a high R value, the growth of pure Ti 3 SiC 2 thin continuous sub-layers from solid–gas reaction is observed for short deposition times. But for long deposition times, the simultaneous growth of additional Ti 5 Si 3 C x and TiC sub-layers occurs from solid state diffusion when the initial Ti 3 SiC 2 sub-layer thickness exceeds about 1 μm. In that case, the repeating of the sequence results in the further conversion of the additional phases into new Ti 3 SiC 2 sub-layers from solid state reactions involving TiSi 2 as an intermediate phase and SiC.
- Published
- 2006
29. Wetting and infiltration of carbon by liquid silicon
- Author
-
N. Eustathopoulos, Olivier Dezellus, Fiqiri Hodaj, and S. Jacques
- Subjects
Molten silicon ,Materials science ,Silicon ,Liquid silicon ,Mechanical Engineering ,Drop (liquid) ,chemistry.chemical_element ,Mineralogy ,Infiltration (hydrology) ,Sessile drop technique ,chemistry ,Mechanics of Materials ,General Materials Science ,Wetting ,Composite material - Abstract
The wettability of carbon materials by molten silicon was investigated at 1430∘C under vacuum by using the dispensed drop variant of the sessile drop technique. The results are compared with data in the literature and used to contribute to a comprehensive understanding of wetting in the liquid-Si/solid-C system. Consequences on the dynamics of Liquid Silicon Infiltration (LSI) processes are discussed.
- Published
- 2005
30. Vapour-Liquid-Solid Induced Localised Growth of Heavily Al Doped 4H-SiC on Patterned Substrate
- Author
-
Phillippe Godignon, Christophe Jacquier, Josep Montserrat, Yves Monteil, Olivier Dezellus, and Gabriel Ferro
- Subjects
Materials science ,Chemical engineering ,Mechanics of Materials ,Mechanical Engineering ,Doping ,Metallurgy ,General Materials Science ,Liquid solid ,Condensed Matter Physics ,Patterned substrate - Published
- 2004
31. Progress in modelling of chemical-reaction limited wetting
- Author
-
Fiqiri Hodaj, Olivier Dezellus, and Nicolas Eustathopoulos
- Subjects
Materials science ,Silicon ,Kinetics ,Mineralogy ,chemistry.chemical_element ,Thermodynamics ,Chemical reaction ,Contact angle ,chemistry ,visual_art ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Reactivity (chemistry) ,Wetting ,Ceramic ,Carbon - Abstract
In reactive metal/ceramic systems the wetting rate of small, millimeter sized droplets on smooth ceramic surfaces is controlled by the slower of two successive phenomena that intervene in the reaction process: diffusive transport of reacting species to or from the triple line, and local reaction kinetics at the triple line. The first case, of diffusive wetting, was modelled by Mortensen et al. [Scripta mater. 36 (1997) 645] a few years ago. The purpose of this paper is to present progress accomplished during the last few years in modelling the second type of wetting controlled by the reaction process at or close to the triple line. The predictions of equations derived from a model describing the change in contact angle and spreading rate with time are compared with experimental results obtained for different silicon alloys on carbon substrates.
- Published
- 2003
32. Influence of evaporation–condensation in reactive spreading
- Author
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Nicolas Eustathopoulos, S. Janaqi, Olivier Dezellus, Fiqiri Hodaj, Laboratoire de thermodynamique et physico-chimie métallurgiques (LTPCM), Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG), Laboratoire de Génie Informatique et Ingénierie de Production (LGI2P), IMT - MINES ALES (IMT - MINES ALES), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)
- Subjects
010302 applied physics ,Auger electron spectroscopy ,Materials science ,Polymers and Plastics ,Drop (liquid) ,Ultra-high vacuum ,Metals and Alloys ,Analytical chemistry ,[CHIM.MATE]Chemical Sciences/Material chemistry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Auger ,Metal ,Contact angle ,visual_art ,0103 physical sciences ,Ceramics and Composites ,visual_art.visual_art_medium ,Evaporation condensation ,Wetting ,Composite material ,0210 nano-technology - Abstract
In reactive wetting, considerable acceleration of spreading rate is usually observed in the high contact angle (short spreading time) range in comparison to the low contact angle range. This study examines the possibility to explain this acceleration by an evaporation–condensation process which may occur under high vacuum in front of the triple line. For this purpose, a method is developed to evaluate the thickness of the reaction product in front of the triple line during spreading. This method is based on calculations of ballistic exchange in vacuum between the drop and the substrate surfaces combined with Auger spectroscopic analysis of the substrate surface. The method is applied to Cu–40 at% Si and Cu–1.5 at% Cr droplets on vitreous carbon systems.
- Published
- 2002
33. Chemical reaction-limited spreading: the triple line velocity versus contact angle relation
- Author
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Nicolas Eustathopoulos, Olivier Dezellus, Fiqiri Hodaj, Laboratoire de thermodynamique et physico-chimie métallurgiques (LTPCM), and Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)
- Subjects
Materials science ,Polymers and Plastics ,020502 materials ,Drop (liquid) ,Ultra-high vacuum ,Metals and Alloys ,Mineralogy ,chemistry.chemical_element ,[CHIM.MATE]Chemical Sciences/Material chemistry ,02 engineering and technology ,Mechanics ,021001 nanoscience & nanotechnology ,Copper ,Chemical reaction ,Electronic, Optical and Magnetic Materials ,Physics::Fluid Dynamics ,Contact angle ,Condensed Matter::Materials Science ,Nickel ,Sessile drop technique ,0205 materials engineering ,chemistry ,Ceramics and Composites ,Wetting ,0210 nano-technology - Abstract
International audience; The mechanisms of reaction-limited spreading of molten copper and nickel silicides on carbon substrates are studied by the dispensed drop variant of the sessile drop technique under high vacuum. Both std. wetting expts. and expts. which sep. the effect of time and instantaneous contact angle on spreading rate are carried out. Equations are derived for the time-dependent variation of contact angle and spreading rate.
- Published
- 2002
34. Spreading of Cu–Si alloys on oxidized SiC in vacuum: experimental results and modelling
- Author
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Olivier Dezellus, Fiqiri Hodaj, Nicolas Eustathopoulos, C. Rado, and J.N. Barbier
- Subjects
Materials science ,Polymers and Plastics ,Drop (liquid) ,Metallurgy ,Alloy ,Ultra-high vacuum ,technology, industry, and agriculture ,Metals and Alloys ,Oxide ,engineering.material ,equipment and supplies ,Electronic, Optical and Magnetic Materials ,Contact angle ,chemistry.chemical_compound ,stomatognathic system ,chemistry ,Ceramics and Composites ,Silicon carbide ,engineering ,Melting point ,Wetting ,Composite material - Abstract
The wetting behaviour of a Cu–40 at.% Si alloy, non-reactive with SiC, on oxidized (0001) faces of α-SiC single crystals is studied at temperatures close to the melting point of copper by the “dispensed drop” technique under high vacuum. The experiments focused on wetting kinetics to determine the mechanisms controlling the rate of spreading under conditions allowing for “in situ” deoxidation of silicon carbide. It is shown that spreading occurs in three stages: (i) an initial stage consisting of a rapid spreading of the alloy on the oxidized SiC up to a contact angle which is close to that on vitreous silica, (ii) a second stage with a zero spreading rate during which the alloy goes through the oxide layer by dissolution near the triple line allowing an intimate contact between the alloy and the SiC surface to be established, and (iii) a final stage during which the alloy spreads with a constant rate up to a contact angle equal to that of clean SiC. These results are interpreted on the basis of a dissolution–diffusion–evaporation process occurring in the vicinity of the solid–liquid–vapour triple line.
- Published
- 2002
35. On the Liquid/Solid Phase Equilibria in the Al-Rich Corner of the Al-Si-Ti Ternary System
- Author
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Olivier Dezellus, Jérôme Andrieux, J.-C. Viala, B. Gardiola, M. Lomello-Tafin, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire SYstèmes et Matériaux pour la MEcatronique (SYMME), and Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])
- Subjects
isopleth ,aluminum alloys ,Ternary numeral system ,Chemistry ,differential scanning calorimetry (DSC) ,invariant point ,isotherm ,Metals and Alloys ,liquidus surface ,Liquidus ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Condensed Matter Physics ,Microstructure ,Isothermal process ,law.invention ,Crystallography ,Projection (relational algebra) ,law ,Phase (matter) ,Content (measure theory) ,Materials Chemistry ,Crystallization ,ComputingMilieux_MISCELLANEOUS ,ternary system - Abstract
The nature of liquid-solid phase equilibria in the Al-rich corner of the Al-Si-Ti system are determined by drawing three isothermal sections at 620, 680 and 727 °C. The solubility of Ti in Al-Si liquids is determined for four different compositions (0, 9, 13 and 18 at.%Si) at temperature below 800 °C. Combination of the two sets of experimental results leads to an attempt of liquidus projection. The primary crystallization surface of Al3Ti is found to extend up to 9.5 at.%Si in the liquid phase at 620 °C and 11 at.%Si at 727 °C. The solubility of Ti is found to be not significantly dependent on the Si content of the liquid. From DSC measurements and deduction on microstructure, the last invariant reaction of the solidification path is found to be quasi-peritectic: $${\text{L}} + \uptau_{1} - {\text{Ti}}_{7} {\text{Al}}_{5} {\text{Si}}_{12} \Leftrightarrow {\text{Al}} + {\text{Si}} .$$
- Published
- 2014
36. On the Solubility of Group IV Elements (Ti, Zr, Hf) in Liquid Aluminum Below 800°C
- Author
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Olivier Dezellus, B. Gardiola, Jérôme Andrieux, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Thermodynamic equilibrium ,Thermodynamics ,Hydrochloric acid ,02 engineering and technology ,Liquidus ,01 natural sciences ,chemistry.chemical_compound ,Transition metal ,0103 physical sciences ,Materials Chemistry ,Binary system ,Solubility ,CALPHAD ,Dissolution ,010302 applied physics ,aluminum alloys ,binary system ,Metallurgy ,Metals and Alloys ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,liquidus ,chemistry ,experimental techniques ,0210 nano-technology - Abstract
International audience; The solubility of group IV transition metals Ti, Zr, and Hf in liquid Al was measured by the settling technique coupled with ICP-AES analysis after dissolution in hydrochloric acid. The kinetic aspect of the settling technique was studied in order to show that, after a cooling step, thermodynamic equilibrium between the liquid and solid phases could be achieved after only 1 h. Finally, it was verified that solubility values obtained after a cooling or a heating step were fully consistent. The present results demonstrate that the immersion-and-settling technique allows reliable solubility values to be determined. The results confirm the values previously reported in the literature and the good description for the three binaries by the existing CALPHAD optimizations concerning the liquidus below 800 C.
- Published
- 2014
37. Controlling Adherence
- Author
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Thomas Pardoen, Olivier Dezellus, Muriel Braccini, IMAP, Université Catholique de Louvain = Catholic University of Louvain (UCL), Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de thermodynamique et physico-chimie métallurgiques (LTPCM), and Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)
- Subjects
[PHYS]Physics [physics] ,020502 materials ,02 engineering and technology ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,[PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph] ,mechanical anchoring ,0205 materials engineering ,adherence control ,[CHIM]Chemical Sciences ,biomimetics ,0210 nano-technology ,practical applications ,ComputingMilieux_MISCELLANEOUS ,dissipative mechanisms - Abstract
International audience
- Published
- 2012
38. Microstructural and mechanical comparison of Ti+15%TiCp composites prepared by free sintering, HIP and extrusion
- Author
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Frank Montheillet, Olivier Dezellus, Nikhil Karnatak, Sébastien Saunier, Jean-Baptiste Fruhauf, Jérôme Roger, Christophe Desrayaud, Sophie Gourdet, Nathalie Peillon, Département Rhéologie, Microstructure, Thermomécanique (RMT-ENSMSE), École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-SMS, UMR 5146 - Laboratoire Claude Goux (LCG-ENSMSE), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), EADS Innovation Works [Toulouse], EADS - European Aeronautic Defense and Space, Mecachrome, Mecach, and Département Mécanique et Procédés d'Elaboration (MPE-ENSMSE)
- Subjects
REINFORCED TITANIUM ,Materials science ,Mechanical properties . TITANIUM MATRIX COMPOSITES ,ALLOYS ,EBSD ,Sintering ,TEXTURE ,02 engineering and technology ,DIFFRACTION ,01 natural sciences ,TI-C ,Powder metallurgy ,TI6AL4V/TIC/10P ,0103 physical sciences ,Ultimate tensile strength ,General Materials Science ,Texture (crystalline) ,Composite material ,Titanium matrix composites ,Microstructure ,010302 applied physics ,Rietveld refinement ,Mechanical Engineering ,Metallurgy ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Ti/TIC reaction ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,FRACTURE ,Mechanics of Materials ,Extrusion ,0210 nano-technology ,BEHAVIOR ,Electron backscatter diffraction - Abstract
International audience; Ti +15%TiCp composites were prepared by three different powder metallurgy techniques: free sintering, HIPing and direct powder extrusion. The microstructures and textures were characterized by EBSD while the Ti/TiC reaction, which takes place during heat treatment, was characterized using X-ray diffraction and Rietveld analysis. The mechanical properties were obtained by the mean of tensile tests. TiC particles effectively reinforce the strength of the Ti matrix by at least 40% indicating the Ti/TiC reaction did not deteriorate the mechanical properties. The correlation between the microstructural features and the mechanical properties is discussed and the processes are compared. Direct powder extrusion was shown to be the most suitable process to obtain ductile composites (epsilon = 4.6%).
- Published
- 2012
39. Transformation Kinetics and Resulting Microstructure in MMC Reinforced with TiC Particles
- Author
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Moukrane Dehmas, Nikhil Karnatak, J.C. Viala, Alice Courleux, Guillaume Geandier, Olivier Dezellus, Olivier Martin, Mickael Mourot, Elisabeth Aeby-Gautier, Frédéric Danoix, Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'étude des textures et application aux matériaux (LETAM), Université Paul Verlaine - Metz (UPVM)-Centre National de la Recherche Scientifique (CNRS), Mecachrome, Mecach, 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), 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 ,Nucleation ,02 engineering and technology ,Atom probe ,01 natural sciences ,law.invention ,Matrix (chemical analysis) ,law ,Phase (matter) ,Powder metallurgy ,0103 physical sciences ,X-Ray Diffraction (XRD) ,[CHIM.CRIS]Chemical Sciences/Cristallography ,[CHIM]Chemical Sciences ,General Materials Science ,Electron Microscopy ,Metal Matrix Composite (MMC) ,Chemical composition ,010302 applied physics ,Kinetic ,Metallurgy ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,Atomic and Molecular Physics, and Optics ,Synchrotron ,Chemical engineering ,Chemical Reactivity ,0210 nano-technology - Abstract
International audience; The phase transformation kinetics on cooling and resulting microstructures of steel-based matrix composites (MMC) reinforced with TiC particles by powder metallurgy were studied. In addition, the phase transformation kinetics of the MMC were compared to those of the same steel without TiC and consolidated in the same conditions. The presence of TiC particles strongly favors the diffusive transformations in the steel matrix of the MMC. Different complementary techniques (XRD, SEM, TEM/EDX, atom probe tomography, in situ synchrotron XRD) were performed to analyze the chemical reactivity between TiC particles and the steel powders occurring during consolidation process and further heat treatments. Composition changes in the TiC as well as in the matrix were characterized. The chemical composition after treatment in the TiC particles tends toward the thermodynamic calculations with ThermoCalc. The effect of changes in chemical composition and the role of TiC particles acting as new favorable nucleation sites are discussed in regards to the obtained results.
- Published
- 2011
40. Thermodynamic modelling of the Ag-Cu-Ti ternary system
- Author
-
Suzana G. Fries, Olivier Dezellus, Raymundo Arroyave, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Department of Mechanical Engineering and Materials Science, Texas A&M University [College Station], Interdisciplinary Centre for Advanced Materials Simulation (ICAMS), and Ruhr-Universität Bochum [Bochum]
- Subjects
Materials science ,Spinodal decomposition ,Intermetallic ,Thermodynamics ,02 engineering and technology ,Flory–Huggins solution theory ,01 natural sciences ,braze alloy ,0103 physical sciences ,Materials Chemistry ,Ceramic ,Physical and Theoretical Chemistry ,CALPHAD ,Ag-Cu-Ti ,Phase diagram ,010302 applied physics ,Ternary numeral system ,Metallurgy ,Metals and Alloys ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,phase diagram ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology ,Ternary operation - Abstract
The Ag–Cu–Ti system is important for brazing applications, particularly for ceramic joining. This system is characterized by numerous intermetallics in the Cu–Ti binary and the existence of a miscibility gap in the liquid phase. For applications, knowledge of the phase equilibria, invariant reactions in the temperature range of interest and thermodynamic activity values (mainly of Ti) are important. Thermodynamic model parameters for all the stable phases in the Ag–Cu, Cu–Ti and Ag–Ti systems, previously obtained using the Calphad method and available in the literature are used. A new thermodynamic description for the ternary interaction parameter of the liquid is obtained from experimental informations. Ti2Cu and Ti2Ag which have the same crystallographic structure were modelled as a single phase. The same was done for TiCu and TiAg. Finally, solid solubility of Ag in the Ti–Cu intermetallics is taken into account. The parameters obtained in this assessment are later used for the calculation of selected sections that can be useful for research and applications in the field of joining with Ti-activated Ag–Cu braze.
- Published
- 2011
41. Mechanical testing of titanium/aluminium-silicon interface: Effect of T6 heat treatment
- Author
-
Olivier Dezellus, J.C. Viala, D. Rouby, Françoise Bosselet, M. Zhe, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), 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), Laboratoire des Multimatériaux et Interfaces ( LMI ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique ( CNRS ), Matériaux, ingénierie et science [Villeurbanne] ( MATEIS ), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique ( CNRS ) -Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), and Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA )
- Subjects
Testing ,Reaction zones ,Titanium castings ,Mechanical properties ,02 engineering and technology ,Si-particle ,01 natural sciences ,Cold waters ,Joint damages ,[SPI.MAT]Engineering Sciences [physics]/Materials ,Load levels ,Failure (mechanical) ,Aluminium ,Test pieces ,General Materials Science ,Composite material ,Bimetallic strip ,Eutectic system ,010302 applied physics ,Quenching ,Titanium ,Chemically bonded ,Silicon interface ,Chemical bonds ,Mechanical behaviour ,Joining ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Casting ,Mechanical properties testing ,Bending tests ,Mechanics of Materials ,0210 nano-technology ,Silicon ,Materials science ,Alloy ,[ SPI.MAT ] Engineering Sciences [physics]/Materials ,chemistry.chemical_element ,engineering.material ,Heat treatment ,Push-out ,Si matrix ,0103 physical sciences ,Titanium alloys ,T6 heat treatment ,Mechanical Engineering ,Damage mechanism ,Aluminium alloys ,Bimetallic assemblies ,Transverse section ,Aluminum alloys ,Push-out tests ,chemistry ,Weakening effect ,engineering ,Fracture surfaces ,Joint strength ,Aluminum ,Surface reactions - Abstract
cited By 12; International audience; A previous paper reported on the mechanical behaviour of insert-moulded Ti/Al-7Si bimetallic test pieces as studied by a classical push-out test as well as a variant: the circular bending test. When a chemical bond was formed at the Ti/Al-7Si interface, promising results were obtained in terms of joint strength and damage mechanism (Dezellus et al., 2008 [1]). As a continuation, the aim of the present work was to examine the influence on this mechanical behaviour of a T6 heat treatment (re-heating for 10. h at 540 °C, quenching in cold water and ageing for 6. h at 170 °C) applied to the as-moulded Ti/Al-7Si test pieces. For that purpose, push-out and circular bending tests were performed on heat-treated samples, and the results were correlated with a characterization of the morphology, the constitution and composition of both transverse sections through the metal/metal reaction zone and fracture surfaces, as revealed after removal of the Ti insert. As expected, applying the T6 heat treatment to chemically bonded Ti/Al-7Si bimetallic assemblies resulted in an improvement of the mechanical properties of the Al-7Si matrix itself. Moreover, a significant increase of the load level for the onset of joint damage in push-out mode was observed. Concerning the damage mechanism, the presence of angular Si particles in the eutectic region of the Al-7Si matrix near the interface had a weakening effect. After T6 solution heat-treatment, the shape of the Si particles changed from angular to globular. Moreover, due to the formation of Si-rich compounds at the Al-7Si/Ti interface, Si diffuses from the alloy towards the Ti rod and the size and number of Si particles became significantly decreased near the insert/alloy interface. These two features explained the favourable influence of the T6 heat-treatment on the mechanical properties of the Ti/Al-7Si assemblies. © 2010 Elsevier B.V.
- Published
- 2011
42. Chemical Changes at the Interface Between Low Carbon Steel and an Al-Si Alloy During Solution Heat Treatment
- Author
-
J.C. Viala, M. Zhe, B. Gardiola, Olivier Dezellus, Muriel Braccini, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), 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), and Région Rhône-Alpes, Cluster MACODEV
- Subjects
Interdiffusion ,Materials science ,Kirkendall effect ,Carbon steel ,Intermetallics ,Diffusion ,Alloy ,Intermetallic ,chemistry.chemical_element ,02 engineering and technology ,engineering.material ,Aluminium ,Materials Chemistry ,Aluminium alloy ,Composite material ,Casting ,020502 materials ,Metallurgy ,Metals and Alloys ,Aluminium alloys ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Diffusion Paths ,Joining ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Atomic diffusion ,0205 materials engineering ,chemistry ,13. Climate action ,Steel ,visual_art ,engineering ,visual_art.visual_art_medium ,0210 nano-technology - Abstract
International audience; The aim of this work was to characterize the chemical changes during solid state solution heat treatment of a metallurgically bonded steel/Al-Si interface. For this purpose, low carbon steel plates covered with the A-S7G03 aluminium alloy (7wt%Si, 0.3wt%Mg analogous to A356) were prepared by dip coating, water-quenching to room temperature and reheating in the solid state at 480-560°C for 3 to 160 hours. Upon reheating at 535 °C, a reaction layer was observed to grow at the interface between steel and the iron-saturated Al-Si alloy. As long as an intimate contact could be maintained, the total thickness, x, of the reaction layer increased with time, t, according to a nearly parabolic growth law x2 = K.t-b. At 535°C, the value of the growth constant was K = 4.045 x 10-14 m2s-1. This constant was found to be thermally activated [K = K0exp (-Q/RT)] with K0 = 4.37 x 10-4m2s-1 and Q =153kJ.mole-1. The whole chemical interaction process was controlled by solid state volume diffusion and the reaction layer sequence corresponded to a diffusion path in the Al-Fe-Si phase diagram. A striking feature of the reaction process is the unbalanced diffusion of aluminium atoms through the reaction zone which rapidly results in the formation of Kirkendall voids. As these voids coalesce, solid state diffusion becomes more and more difficult and the steel/alloy bond gets weakened. Oxidation appears to be an aggravating factor, where applicable.
- Published
- 2011
43. Further Evidence of Nitrogen Induced Stabilization of 3C-SiC Polytype during Growth from a Si-Ge Liquid Phase
- Author
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J.C. Viala, Gabriel Ferro, Christian Brylinski, Patrick Chaudouët, Olivier Kim-Hak, Olivier Dezellus, Davy Carole, Jean Lorenzzi, Didier Chaussende, Nikoletta Jegenyes, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des matériaux et du génie physique (LMGP ), and Institut National Polytechnique de Grenoble (INPG)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
010302 applied physics ,Materials science ,Stereochemistry ,Mechanical Engineering ,Analytical chemistry ,chemistry.chemical_element ,Liquid phase ,Liquid Phase Epitaxy (LPE) ,Polytype Stability ,02 engineering and technology ,Partial pressure ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Nitrogen ,Lattice constant ,chemistry ,Mechanics of Materials ,Impurity ,0103 physical sciences ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,[CHIM]Chemical Sciences ,General Materials Science ,0210 nano-technology - Abstract
International audience; The influence of nitrogen impurity on the stabilization of 3C-SiC polytype has been studied during vapour-liquid-solid (VLS) growth on 6H-SiC(0001) seed with Si-Ge melt. By changing the partial pressure of N2 during growth, it was found that the proportion of 3C-SiC inside the grown material increases with N2 partial pressure. 6H inclusions are only found for high purity (low N2 content) conditions. The possible interactions proposed to explain this effect are divided in two effects: i) lattice parameter modification and ii) surface induced lateral enlargement variation. A combination of both effects is suspected.
- Published
- 2010
44. Fundamental issues of reactive wetting by liquid metals
- Author
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Nicolas Eustathopoulos, Olivier Dezellus, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Science et Ingénierie des Matériaux et Procédés (SIMaP), and 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)
- Subjects
wetting ,Materials science ,capillarity ,020502 materials ,Mechanical Engineering ,ceramic ,Thermodynamics ,metals ,Bonding in solids ,02 engineering and technology ,[CHIM.MATE]Chemical Sciences/Material chemistry ,ceramics ,021001 nanoscience & nanotechnology ,reactivity ,high temperature ,0205 materials engineering ,alloys ,Mechanics of Materials ,visual_art ,visual_art.visual_art_medium ,Physical chemistry ,General Materials Science ,Wetting ,Ceramic ,0210 nano-technology - Abstract
International audience; Many pure metals and alloys do not wet covalent or ionocovalent ceramics and adhere weakly on them .This is the case for the low or moderate melting point metals Pb,Sn,In ,Ag,Au,Cu on the various forms of carbon(graphite ,diamond, vitreous carbon ..), on stable oxides (alumina, silica ,magnesia...) as well as on silicon and boron nitrides. A strong improvement in wetting can be obtained by certain alloying elements able to modify in situ the metal/ceramic interface by reaction with the ceramic .Reactivity is probably the major specific characteristic of wetting at high temperatures. The presentation will focus on the progress made during the last five years in the understanding of driving force and spreading kinetics of reactive wetting. A special attention will be paid to discuss the contribution on reactive wetting of the two following processes, adsorption at the initial metal/ceramic interface and formation of a 3D compound at the interface. The presentation will focus on the progress made during the last five years in the understanding of driving force and spreading kinetics of reactive wetting. A special attention will be paid to discuss the contribution of adsorption at the initial metal/ceramic interface and formation of a 3D interfacial compound.
- Published
- 2010
45. Low-Temperature Interface Reaction between Titanium and the Eutectic Silver-Copper Brazing Alloy
- Author
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Olivier Dezellus, J.C. Viala, Jérôme Andrieux, Françoise Bosselet, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Materials science ,Alloy ,Intermetallic ,Nucleation ,chemistry.chemical_element ,metals ,02 engineering and technology ,engineering.material ,chemical potential gradients ,Materials Chemistry ,Eutectic bonding ,diffusion paths ,intermetallics ,Dissolution ,Eutectic system ,ternary system ,020502 materials ,Metallurgy ,Metals and Alloys ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Atomic diffusion ,0205 materials engineering ,chemistry ,engineering ,0210 nano-technology ,Titanium - Abstract
International audience; Reaction zones formed at 790 °C between solid titanium and liquid Ag-Cu eutectic alloys (pure and Ti-saturated) have been characterized. When pure Ag-Cu eutectic alloy with 40 at.% Cu is used, the interface reaction layer sequence is: alpha-Ti / Ti2Cu / TiCu / Ti3Cu4 / TiCu4 / L. Because of the fast dissolution rate of Ti in the alloy, the reaction zone remains very thin (3-6 µm) whatever the reaction time. When the Ag-Cu eutectic alloy is saturated in titanium, dissolution no longer proceeds and a thicker reaction zone with a more complex layer sequence grows as the reaction time increases. Four elementary chemical interaction processes have been identified in addition to Ti dissolution in the liquid alloy. These are growth of reaction layers on Ti by solid state diffusion, nucleation and growth from the liquid of TiCu4, isothermal solidification of silver and, finally, chemical conversion of the Cu-Ti compounds by reaction-diffusion in the solid state. A mechanism combining these processes is proposed to account for the constitution of Ti/ Ag-Cu/ Ti joints brazed at 780-800 °C.
- Published
- 2009
46. Transient liquid phase bonding of titanium to aluminium nitride
- Author
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Françoise Bosselet, M. Sacerdote-Peronnet, Nicolas Eustathopoulos, Olivier Dezellus, J.C. Viala, Fiqiri Hodaj, T. Baffie, Jérôme Andrieux, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Département Technique Conversion et Hydrogène (DTCH), Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux (LITEN), Institut National de L'Energie Solaire (INES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de L'Energie Solaire (INES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Science et Ingénierie des Matériaux et Procédés (SIMaP), and 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)
- Subjects
Isothermal solidification ,Materials science ,Annealing (metallurgy) ,Nucleation ,chemistry.chemical_element ,02 engineering and technology ,Interfacial reactivity ,01 natural sciences ,Isothermal process ,Fusion welding ,chemistry.chemical_compound ,0103 physical sciences ,General Materials Science ,010302 applied physics ,Experimental study ,Aluminium nitride ,Mechanical Engineering ,Metallurgy ,Metal to ceramic brazing ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,chemistry ,Mechanics of Materials ,Transient liquid phase bonding ,Ag–Cu alloy ,Melting point ,Wetting ,0210 nano-technology ,Titanium - Abstract
International audience; Titanium has been successfully joined to aluminium nitride AlN at a temperature as low as 795 ◦C, using Ag–Cu Cusil® commercial braze alloy. While reactive wetting and spreading proceeds at the AlN/braze alloy interface, chemical interactions develop at the titanium side rendering possible isothermal solidification of the joint. The determining factor in the solidification process is the fast formation of TiCu4 crystals by heterogeneous nucleation and growth in the liquid phase. As a consequence, the braze alloy is depleted in Cu and solid Ag precipitates. After annealing, the re-melting temperature of the resulting joint can be increased up to about 910 ◦C which is nearly 130 ◦C higher than the melting point of the starting braze alloy.
- Published
- 2008
47. Local reinforcement of magnesium base castings with mild steel inserts
- Author
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D. Rouby, J.C. Viala, Olivier Dezellus, Françoise Bosselet, E. Guiot, M. Sacerdote-Peronnet, Mateis, Laboratoire, 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), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Materials science ,Alloy ,Base (geometry) ,chemistry.chemical_element ,02 engineering and technology ,engineering.material ,[SPI.MAT] Engineering Sciences [physics]/Materials ,Steel bar ,01 natural sciences ,[SPI.MAT]Engineering Sciences [physics]/Materials ,0103 physical sciences ,General Materials Science ,Reinforcement ,Joint (geology) ,Bimetallic strip ,ComputingMilieux_MISCELLANEOUS ,010302 applied physics ,Insert (composites) ,Magnesium ,Mechanical Engineering ,Metallurgy ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,chemistry ,Mechanics of Materials ,engineering ,0210 nano-technology - Abstract
The functionality of structural light alloy castings can be considerably improved by inserting into them upon moulding iron base local reinforcements. A necessary condition to obtain tight joints with good load transfer is that a sound metallurgical bond is formed at the insert/alloy interface. However, many physical–chemical factors play an important part in the mechanical behaviour of the joint. To acquire a better insight into this issue, bimetallic samples were prepared by immersing a mild steel bar (5 mm in diameter) in magnesium base Mg–Al alloy melts held at 650–750 °C in a graphite crucible (mean diameter 19 mm). Different processing conditions were used to vary the degree of chemical interaction at the insert/alloy interface. After melt solidification, the bimetallic samples were cut into slices (2–10 mm thick) and push out testing was performed on these slices. Attempts have been made to relate the main features of the load–displacement curves thus obtained with the nature and extent of the transition zones formed at the insert/alloy interface.
- Published
- 2007
48. Diffusion-limited reactive wetting: effect of interfacial reaction behind the advancing triple line
- Author
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Andreas Mortensen, Olivier Dezellus, Nicolas Eustathopoulos, J.N. Barbier, Fiqiri Hodaj, Science et Ingénierie des Matériaux et Procédés (SIMaP), and 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)
- Subjects
Materials science ,Kinetics ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,01 natural sciences ,Physics::Fluid Dynamics ,chemistry.chemical_compound ,Sessile drop technique ,0103 physical sciences ,General Materials Science ,[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,Growth rate ,Helium ,010302 applied physics ,Scattering ,020502 materials ,Mechanical Engineering ,Drop (liquid) ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Condensed Matter::Soft Condensed Matter ,0205 materials engineering ,chemistry ,Mechanics of Materials ,Chemical physics ,Wetting ,Chromium carbide - Abstract
Using the “dispensed drop” variant of the sessile drop technique, spreading kinetics of dilute Cu–Cr alloys on smooth vitreous carbon substrates are measured under helium microleak conditions. In this system, it is known that the drop spreading rate is controlled by diffusion of the reactive atom species (Cr) from the bulk liquid to the triple line, where wetting is induced by formation of an interfacial layer of chromium carbide. Microstructural characterization of rapidly cooled drops shows that growth of the interfacial reaction product layer continues behind the moving solid–liquid–vapor triple line. The spreading velocity is modeled by finite-difference numerical analysis of diffusion near the triple line in the presence of continued interfacial reaction, simplifying the growth rate as being constant and using realistic parameter values. We show that continued interfacial reaction explains the dependence of the triple line spreading rate on the instantaneous wetting angle that is observed in this system.
- Published
- 2007
49. The role of van der Waals interactions on wetting and adhesion in metal/carbon systems
- Author
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Olivier Dezellus, Nicolas Eustathopoulos, Laboratoire de thermodynamique et physico-chimie métallurgiques (LTPCM), and Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)
- Subjects
gold wetting adhesion carbon substrate ,Materials science ,copper wetting adhesion carbon substrate ,metal wetting adhesion carbon substrate ,chemistry.chemical_element ,02 engineering and technology ,London dispersion force ,Contact angle ,symbols.namesake ,Sessile drop technique ,General Materials Science ,Graphite ,graphite substrate metal wetting adhesion ,020502 materials ,Mechanical Engineering ,Metals and Alloys ,Adhesion ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0205 materials engineering ,chemistry ,Mechanics of Materials ,Chemical physics ,symbols ,Physical chemistry ,Wetting ,van der Waals force ,0210 nano-technology ,Carbon - Abstract
International audience; Sessile drop expts. using pure Cu and Au on different C substrates under high vacuum showed that these metals wet monocryst. graphite better than vitreous C with the corresponding differences in the work of adhesion being 50-60%. These results were interpretted satisfactorily by assuming that the predominant interactions at the surface are van der Waals interactions due to dispersion forces. For nonreactive metal/C systems, wetting and adhesion of a metal is expected to vary only slightly around its m.p. This is also expected to be true for any metal/ceramic system in which adhesion is ensured mainly by van der Waals interactions.
- Published
- 1999
50. Étude expérimentale et évaluation thermodynamique du système Al-C-Mg
- Author
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Deffrennes, Guillaume, Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon, Olivier Dezellus, and Jérome Andrieux
- Subjects
Thermodynamic properties ,Al2MgC2 ,Optimisation thermodynamique ,CALPHAD ,Al4C3 ,Al-C-Mg ,Thermodynamic optimization ,Propriétés thermodynamique ,Structure ,[CHIM.MATE]Chemical Sciences/Material chemistry ,DFT - Abstract
To reduce its environmental footprint by lightweight vehicles design, the transportation sector relies on an increased use of magnesium based materials. Computational approaches relying on the use of thermodynamic databases can enable the accelerated development of such materials. Commercial thermodynamic databases regarding the Al-C-Mg are unreliable due to a lack of data. As a result, no guidance can be provided regarding the underlying mechanisms of the grain refinement of Mg-Al alloys by carbon inoculation which are debated in the literature. Therefore, the purpose of this study was to provide a reliable thermodynamic assessment of the Al-C-Mg system. First of all, the literature regarding the Al-C-Mg system and its subsystems was critically reviewed. This review highlighted disagreements and shortages regarding the data related to the Al-C and Al-C-Mg systems. Secondly, an experimental procedure based on the use of sealed Ta crucibles was developed. This procedure is promising as it allowed working with magnesium up to 2094 K (1821°C) and 41 bars of pressure. Thirdly, experimental investigation and ab-initio calculations of data related to the Al-C and Al-C-Mg systems were conducted. The heat capacity as well as the standard enthalpy and entropy of formation of Al4C3 and Al2MgC2 were obtained. Furthermore, the crystal structure of Al2MgC2 was confirmed on the basis of single-crystal X-ray diffraction data, and the thermal stability of the ternary carbide was determined. Lastly, CALPHAD optimization of the Al-C and Al-C-Mg systems was conducted on the basis of the critically assessed literature data as well as of those freshly obtained. Self-consistent thermodynamic descriptions of Al2MgC2, (Al,Mg)4C3 as well as the Al-C-Mg liquid phase were obtained. Those descriptions will fuel the thermodynamic databases and will enable the development of Mg-Al alloys and Mg-Al matrix carbon materials reinforced composites. This study provides a convincing argument supporting the fact that Al2MgC2 is responsible for the grain refinement of Mg-Al alloys by carbon inoculation; La diminution de l'impact environnemental de l'industrie des transports par l'allégement des structures des véhicules passe par une utilisation accrue de matériaux à base de magnésium. Ces matériaux peuvent bénéficier d'un développement accéléré par le biais de simulations numériques s'appuyant sur des bases de données thermodynamiques. En ce qui concerne le système Al-C-Mg, les bases de données thermodynamiques commerciales sont incomplètes à cause du nombre insuffisant de données disponibles. Cette lacune est notamment synonyme de l'absence de guide dans l'identification des mécanismes régissant l'affinement de microstructures d'alliages Mg-Al par inoculation de carbone débattus dans la littérature. Par conséquent, l'objectif de cette étude a été d'aboutir à une évaluation thermodynamique complète du système ternaire Al-C-Mg. Dans un premier temps, une étude critique de la littérature concernant le système Al-C-Mg et ses sous-systèmes a été menée. Cette revue a mis en lumière des désaccords et des manques à propos des données relatives aux systèmes Al-C et Al-C-Mg. Dans un second temps, une démarche expérimentale basée sur l'utilisation de creusets scellés en Ta a été développée. La méthodologie mise en place est prometteuse puisqu'elle a permis de travailler avec le magnésium jusqu'à 2094 K (1821°C) et 41 bars de pression. Dans un troisième temps, la détermination expérimentale ainsi que par le calcul DFT de données relatives aux systèmes Al-C et Al- C-Mg a été entreprise. La capacité thermique ainsi que l'enthalpie et l'entropie standard de formation des carbures Al4C3 et T2-Al2MgC2 ont été obtenues. De plus, la structure cristallographique de la phase T2-Al2MgC2 a été confirmée par DRX sur monocristal, et la nature et la température de la décomposition invariante du carbure ternaire ont été déterminées. Dans un dernier temps, une modélisation CALPHAD des systèmes Al-C et Al-C-Mg a été conduite sur la base des données de la littérature sélectionnée de façon critique et de celles nouvellement obtenues. Des descriptions thermodynamiques cohérentes de la phase Al2MgC2, de la solution de Mg dans Al4C3 ainsi que du liquide Al-C-Mg ont été obtenues. Ces descriptions vont alimenter les bases de données thermodynamiques et vont favoriser le développement des alliages Mg-Al et des composites à matrice Mg-Al renforcés par des matériaux carbonés. Cette étude apporte un argument fort supportant le fait que la phase Al2MgC2 est responsable de l'affinement de microstructures d'alliages Mg-Al par inoculation de carbone
- Published
- 2018
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