WorldCat Identities

Douin, Joël

Overview
Works: 25 works in 44 publications in 2 languages and 132 library holdings
Genres: Conference papers and proceedings 
Roles: Author, Other, Thesis advisor, Opponent, Editor
Publication Timeline
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Most widely held works by Joël Douin
Mécanique des milieux continus : introduction à la plasticité des matériaux by Joël Douin( Book )

5 editions published in 1997 in French and held by 76 WorldCat member libraries worldwide

Interfaces and plasticity : proceedings of the Advanced School Meeting 'Dislocations 96' held in Tozeur, Tunisia, October 1996 = Interfaces et plasticité by N Clément( )

8 editions published in 1998 in English and held by 18 WorldCat member libraries worldwide

Proceedings of the Advanced School Meeting 'Dislocations 96' held in Tozeur, Tunisia, October 1996
Comportement mécanique et évolutions microstructurales sous compression quasi-statique et dynamique de polycristaux CFC et HC : effet de la taille des grains by Abdelouahab Ouarem( )

4 editions published in 2012 in French and held by 7 WorldCat member libraries worldwide

The present work is devoted to the analysis of the strain rate and grain size effects on the deformation mechanism activated during plastic deformation of two polycrystalline materials: (i) zinc (Zn), a crystal with hexagonal compact packing structure, having grain size in the micro and ultrafine grain ranges (~ 300 µm and 200 nm, respectively), loaded under quasi-static and dynamic compression conditions, up to a strain rate of ~ 10⁵ s⁻¹ (by use of a Direct Impact Hopkinson Pressure Bars (DIHPB); (ii) electrodeposited nickel (Ni), a face-centered cubic structure with grain size of 5 µm deformed in compression under dynamic conditions using DIHPB. Significant differences in terms of micro-mechanisms of deformation in the two regimes were found: (i) At lower strain rates, up to ~ 10² s⁻¹, dislocation-based plasticity was observed in both Ni and Zn. Extensive twinning occurred only in the case of micrometer grain-sized Zn, indicating a grain size dependence of twinning; (ii) In the dynamic regime (> 10³ s⁻¹) plastic deformation induced a significant increase of the temperature within the samples. This increase of temperature was significant enough to induce recovery and/or dynamic recrystallization. As consequence two phenomena were observed depending on the structure under investigation: for Ni, the resulting microstructure and mechanical properties were similar to that of the initial state, dominated by annealing twins and equiaxed and randomly oriented grains. For micro-grained Zn a tremendous grain refining was found. As a consequence, twinning was inhibited. To clarify this point, additional investigations were carried out on coarse-grained CP-Ti deformed in both quasi-static and dynamic regimes. It was found that twinning was the main deformation mechanism. Indeed, the larger the strain rate and grains size, the larger the twin density. On the one hand, these results clearly demonstrate the grain size effect on the occurrence of mechanical twinning in HCP materials. On the other hand, the effect of the strain rate on twinning was found to depend on the material under investigation. Compared to Ti, the lower homologous temperature T/T m of Zn probably plays a key role, as it may induce dynamic recovery/recrystallization as far as the present experimental conditions are concerned
Étude par microscopie électronique en transmission des microstructures et des micromécanismes de déformation d'alliages de titane béta-métastables by Nicolas Escale( Book )

3 editions published between 2012 and 2015 in French and held by 3 WorldCat member libraries worldwide

The lightening of structure is one of the most important issue in the aircraft industry. The weight saving for future planes could be obtained by the use of materials with very high specific mechanical performances. Titanium alloys have high mechanical properties, a relatively low density, an high damage tolerance and corrosion resistance are particularly interesting to reach this purpose. The aim of this present work is to characterize and understand the fundamental micro-mechanisms of deformation in two titanium alloys: Ti 5553 (Ti-5Al-5Mo-5V-3Cr) and Ti 17 (Ti-5Al-2Sn-2Zr-4Mo-4Cr). These two alloys seem to be good candidates to substitute the Ti64 alloy, which is the aeronautical industry reference. To carry out this study we have characterized by Transmission Electron Microscopy the microstructure, which consists in hexagonal phases embedded in a cubic centered matrix. In situ straining TEM experiments combined with conventional and High Resolution observations allow us to identified and quantified the micro-mechanisms of deformation that influence the plasticity in these materials. So we have determined that the strength is due to several contributions like: a structural hardening, the presence of a local order or the core structure of screw dislocations
Structure fine des dislocations et plasticité dans Ni(3)Ai by Joël Douin( Book )

2 editions published in 1987 in French and held by 3 WorldCat member libraries worldwide

ETUDE DETAILLEE DE L'EVOLUTION DE LA STRUCTURE FINE DES DISLOCATIONS DANS UNE LARGE GAMME DE TEMPERATURE AUTOUR DU PIC DE LIMITE ELASTIQUE (600-700C). ANALYSE CRISTALLOGRAPHIQUE DE LA STRUCTURE ORDONNEE L1::(2) ET DES DEFAUTS PLANS DE CETTE STRUCTURE. PRESENTATION, A PARTIR DE CETTE ANALYSE, DES RESULTATS DES SIMULATIONS ATOMIQUES DE PAROI D'ANTIPHASE. CALCUL DE FORME ET D'ENERGIE DE DISLOCATIONS EN ELASTICITE ANISOTROPE. ANALYSE DU MECANISME DE FORMATION DES DEFAUTS D'EMPILEMENT. ETUDE, EN FONCTION DE LA TEMPERATURE D'ESSAI, DE LA STRUCTURE FINE DES DISLOCATIONS. INFLUENCE D'UNE VARIATION DE COMPOSITION SUR LA MORPHOLOGIE DES DISLOCATIONS
Measurements of strain fields due to nanoscale precipitates using the phase image method( )

1 edition published in 2001 in English and held by 2 WorldCat member libraries worldwide

Owing the phase image method (Hytch, 1998), strain fields can be derived from HREM images. The method is here applied to the nanoscale precipitates responsible for hardening in Aluminum alloys. Since the method is a very sensitive one, we have examined the impact of several aspects of the image quality (noise, fluctuations, distortion). The strain field information derived from the HREM image analysis is further introduced in a simulation of the dislocation motion in the matrix
Microstructure et mécanismes de durcissements associés à la phase T1 dans un alliage Al-Li-Cu de troisième génération by Thomas Dorin( )

1 edition published in 2013 in English and held by 2 WorldCat member libraries worldwide

The age-hardening AA2198 alloy is mainly used in aeronautic applications. The anisotropic T1 - Al2LiCu phase gives the main contribution to strengthening in this system. The main objective of this study is to understand the strengthening mechanisms in terms of interactions between the dislocations and the T1 plate-like precipitates. The first step consists in the development of a characterization procedure adapted to the T1 phase (characterization of the diameter, thickness and volume fraction of the T1 plates). The thermo-mechanical treatment is adapted in order to vary the T1 parameters independently and the yield strength evolution is systematically measured and that permits the investigation of the relationship between the T1 microstructure and the yield strength variations. The experimental data base that is generated allows testing and improving the existing yield strength models. An energetic approach of the shearing mechanisms is used to model precisely the yield strength evolution for a high number of microstructures. The decrease in yield strength after the peak is solely explained by invoking the shearing mechanism. The investigation of the plasticity phenomenon associated to the T1 phase, with the study of the shear bands and of the work hardening behavior, is the last step of this work. A shearing-to-by-passing transition is found to occur for long-over ageing times
Le matériau composite NiAl-Al₂O₃ by Jean-Claude Bihr( Book )

2 editions published in 1996 in French and held by 2 WorldCat member libraries worldwide

Les industries aéronautiques tentent de mettre au point de nouvelles structures plus résistantes et surtout réutilisables en vue d'accélérer la conquête de l'espace. A cet effet, le matériau composite à matrice intermétallique NiAl renforcée par des fibres longues d'alumine semble prometteur et adapté à ces applications. Les travaux présentés concernent a la fois l' élaboration du composite par infiltration liquide sous pression de gaz et l'étude du couplage fibre-matrice (F/M), phénomène prépondérant qui gouverne les caractéristiques macroscopiques du matériau. Le couplage a été étudié par le biais de la microscopie électronique en transmission et de la spectroscopie de photo-électrons X ; une approche thermodynamique du couplage a ete obtenue au travers de l'étude de mouillabilite du renfort par la matrice. Ces différentes caractérisations des interfaces et interphases sont correlées les unes avec les autres pour permettre une compréhension globale des phénomenes de couplage à l'interface F/M
Synthesis of copper/chromium oxide composites by a chemical processing method by Amélie Veillère( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

Etude du gonflement par cavités d'un alliage d'aluminium irradié sous faisceau d'ions by Victor Garric( )

1 edition published in 2019 in French and held by 2 WorldCat member libraries worldwide

L'alliage d'aluminium 6061-T6 (Al-Mg-Si), choisi pour la conception du caisson et du casier du réacteur Jules Horowitz (RJH), doit ses propriétés mécaniques au durcissement structural T6 induit par une précipitation nanométrique : une mise en solution suivie d'une trempe et d'un revenu. En raison de l'épaisseur des composants, la vitesse de trempe obtenue sur les éléments d'un réacteur expérimental est plus faible que celle des pièces fines couramment étudiées. Afin d'étudier l'effet de la vitesse de trempe sur la microstructure et le comportement sous irradiation, trois cubes de 10 cm de côté d'alliage 6061 ont subi un traitement T6 dans trois conditions de trempe (eau, huile, air). A la suite de ces traitements, une caractérisation microstructurale et mécanique a été réalisée sur chaque état.La contribution au gonflement de l'aluminium des cavités qui se forment sous flux de neutrons rapides est mal connue. Par des irradiations ioniques de lames MET à différents niveaux d'endommagement (entre 15 dpa et 100 dpa), une évaluation des modifications microstructurales suivie d'une quantification du gonflement et d'une modélisation a été entreprise.Des irradiations en triple faisceau (W, He, Si) permettant de cumuler les dommages avec l'implantation d'éléments produits en réacteur par transmutation de l'aluminium, ont montré que l'implantation de silicium conduit à l'apparition d'une nouvelle phase riche en Si. En simple faisceau d'ions lourds (Au), les cavités se localisent autour des défauts linéaires et des dispersoïdes, mais en présence d'hélium elles apparaissent aussi réparties dans toute la matrice. Compte tenu des fortes teneurs en hélium implanté, les mesures quantitatives du gonflement ont été réalisées sur les lames irradiées en simple faisceau.Le gonflement mesuré, plus élevé que sous flux neutronique, a conduit à considérer pour la modélisation deux séries de données (ions/neutrons). Les bases d'une modélisation du gonflement par cavités ont été posées, et les paramètres physiques restant à déterminer ont été identifiés
Étude d'un alliage d'aluminium pour l'aéronautique par les techniques avancées de microscopie électronique en transmission by Marion Le Fournier( Book )

2 editions published in 2012 in French and held by 2 WorldCat member libraries worldwide

Le durcissement structural est une voie largement utilisée dans le secteur aéronautique pour répondre aux exigences à la fois d'amélioration des propriétés mécaniques des alliages métalliques et d'allègement de structure. Dans les alliages Al-Li-Cu de la série 2000, le durcissement structural est assuré par la présence des précipités T1 (Al2LiCu) qui modifient localement la matrice cristalline d'aluminium qui les entoure. La compréhension des micromécanismes de déformation, qui nécessite la connaissance des interactions des dislocations avec ces phases durcissantes, impose donc une caractérisation précise des champs de déformation. Dans cet objectif, nous avons développé une approche expérimentale adossée à des modélisations. A partir d'analyses en microscopie électronique en haute résolution (MEHR), couplées à des analyses dites " des phases géométriques " (GPA), une méthode de mesure des champs de déformations suivant trois directions de l'espace est proposée. Nous avons ensuite modélisé les précipités par deux dislocations dissociées parfaitement identifiées de type a/6 <112> qui participent au mécanisme de croissance des phases T1. Par ailleurs, nous avons développé plusieurs modèles basés sur la théorie des dislocations et sur la résolution des équations de la micromécanique dans le réseau réciproque en élasticité linéaire et isotrope, afin de reproduire les champs de déformations induits par les phases durcissantes dans la matrice d'aluminium. Cette approche, couplée à nos observations en MEHR, nous a permis de proposer une description des champs de déformation en extrémité de précipité en accord avec l'expérience
Drains thermiques adaptatifs : cuivre allié / Fibre de Carbone by Amélie Aurélie Mylène Veillere( )

1 edition published in 2009 in French and held by 1 WorldCat member library worldwide

In the field of power electronics, thermal management of silicon chips plays a key role in our ability to increase their performance. Heat generated by the electronic components is dissipated through the heat sink, generally made of Copper that is brazed on to a ceramic substrate. This study focuses on the elaboration of adaptive heat sink material using Copper alloys/Carbon fibers (CF) composite materials which have a good thermal conductivity and a CTE close to the ceramic substrate. In this kind of material, it is necessary to have a strong matrix/reinforcement link in order to optimize transfer properties. Since there is no reaction between Copper and Carbon, a carbide element (Cr or B) is added to the Copper matrix to create this strong chemical bond. A model material has been elaborated by cathode sputtering in order to study the diffusion of the alloying element in the Copper layer and the metallic carbide formation in the interfacial zone. Copper alloy powders, with a given stoichiometry, have also been synthesized by a chemical method. Lastly, composite materials (Cu-B/CF and Cu-Cr/CF) have been elaborated by a powder metallurgy process and their thermal and mechanical properties correlated to the microstructure and the chemistry of the interfacial zones
Effets d'un vieillissement longue durée sur deux alliages d'aluminium de la série 2000 by Nicolas Bello( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

Benefits of the Complementary use of Archaeometry Investigations and Historical Research in the Study of Ancient Airplanes: the Breguet Sahara's Rivets( )

1 edition published in 2014 in English and held by 1 WorldCat member library worldwide

ABSTRACT: The aim of this paper is to show that historical technical archives and complementary physico-chemical studies can be combined to obtain relevant information on the materials and processes used in the manufacturing of a Breguet 765 Sahara airplane. This will be useful both in history of sciences and technology and in the renovation of this more than fifty years old airplane. The Breguet 765 Sahara plane is the last version of a family of French double-deck transport aircraft produced by Breguet between 1948 and 1960. The gathering of multi-disciplinary information from the literature of the period of production with laboratory investigations has revealed that a "new" aluminum-copper-magnesium alloy was used in the rivets of the Breguet 765. The A-U3G alloy was developed to meet properties requirements of the aeronautical industry for joining sheets of aluminum and was used in the Breguet 765 Sahara to strengthen the joints. Analytical techniques included TEM, EPMA microprobe and metallography
Influence des nano-particules d'alumine (Al2O3) et de di-borure de titane (TiB2) sur la microstructure et les propriétés de l'alliage Al-Si9-Cu3-Fe1 pour des applications de fonderie à haute pression by Iban Vicario Gomez( )

1 edition published in 2011 in French and held by 1 WorldCat member library worldwide

The work has been focused on the study of the influence of TiB2 and Al2O3 nano-particles (up to 1 wt. %) on the properties and physical features of an aluminium casting alloy, Al-Si9Cu3Fe1.Samples have been obtained through the High Pressure Die Casting (HPDC) process and compared with unreinforced samples obtained at the same conditions. It has been observed that the Al2O3 and TiB2 particles have a direct influence on several features of the alloy such as the microstructure and precipitating phases as well as in the improvement of the soundness and mechanical and electrical properties. Al2O3 and TiB2 particles can be used to tailor the properties of the alloy and to match the specifications of light weight applications
Métallurgie et comportement mécanique de structures minces brasées pour la production d'échangeurs thermiques by Elodie Catherine Martin( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

This work is devoted to improving the manufacturing process of heat exchangers used in aerospace applications. Heat exchangers included in air conditioning systems for aircraft are produced by brazing stamped thin alloys sheets made of nickel-based alloys, Alloy 600 and Ni 201, or stainless steel, AISI 444. Separation metal sheets and locking bars of Alloy 625 are used to complete the system. The used brazing filler metal BNi-8 is mainly composed of nickel, manganese, silicon and copper. However, brazing defects appear during the manufacture of theheat exchangers can lead to non-integrity of the components. In order to improve the understanding of the phenomena related to brazing, several axes of investigation have been considered. Firstly, the behavior of the brazing filler metal was characterized by studying the melting temperatures as a function of the composition, the microstructure and the associated mechanical properties. In parallel, the base metals were also studied in order to know the evolution of the microstructure and therefore the mechanical properties as a function of the temperature but also of the state of stress present in the metal sheet induced by the stamping. Studying of stamped thin alloys sheets also allowed to understand the behavior of these thin products in hot compression. Finally, in order to get closer to the actual brazing conditions in industrial environment, studies of the coupling of brazing filler metal/base metal from a metallurgical and mechanical point of view have been carried out. All of these studies pursue aim to better understand the phenomena involved during the brazing cycle and to propose improvements for the brazing process (geometry of stamped thin alloys sheets, thermal cycles, used materials, etc.)
Étude de l'alliage de titane TA6V obtenu par fabrication additive : microstructure, élasticité et contraintes résiduelles by Nathan Dumontet( )

1 edition published in 2019 in French and held by 1 WorldCat member library worldwide

Laser Beam Melting is an additive manufacturing process that reaches a sufficient industrialmaturity to start producing parts in series, even if some problems remain. One of the mostcommonly used materials in additive manufacturing but particularly difficult to use is Ti-6Al-4V, thetitanium alloy most commonly used on Earth. Indeed, the cooling kinetics of the parts producedprecipitate a particular microstructure in the material that is still poorly understood, particularly interms of elasticity. In addition, Ti-6Al-4V elaborated trough additive manufacturing suffers from theappearance of significant residual stresses that can cause cracks in the part. Currently, thesolution used to overcome the residual stresses consists of a heat treatment that allows thestresses to be relaxed, without solving the problem of their genesis. The first part of this work isfocused on the study of the microstructure of raw parts and stress released parts after a heattreatment. We were thus able to study the martensitic phase ' using different microscopy anddiffraction techniques. We were able to study the phase transformation from ' to (+) by thermodifferential analysis. In a second step, elasticity was studied experimentally at the macroscopicscale by tensile and acoustic vibration tests, locally by X-ray diffraction and by atomic calculation.These results on elasticity agree that the ' martensitic phase is less rigid and more anisotropicthan the phase. In the third part of this study, the effect of different additive manufacturingparameters on residual stresses was investigated. Residual stresses were determined by differentdiffraction methods, such as X-ray or neutron diffraction, and bridge curvature (BCM). It could beshown that the thermal conductivity of the substrate, the dwell time and the shape of the samplehad a significant effect on residual stresses while no clear effect of the position on the plate, thesample height or the energy density could be shown. These different results provide anunderstanding of the genesis of residual stresses in Ti-6Al-4V parts from the LBM and its elasticbehaviour. All these results provide a better understanding of the problems encountered in theindustrial sector. This work aims at improving the relevance of the choice of process parametersand thus to predict, or even stop, the arrival of blocking points in additive manufacturing
Etude du soudage laser YB : YAG de l'alliage d'aluminium AA6061-T4 : Microstructures, propriétés mécaniques et comportement en corrosion des assemblages by Ameth Faye( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

Weight savings in aeronautical structures and need for new functionalities are going through two technological obstacles: development of new structural materials but also development of innovative assembly solutions, offering alternatives to the mechanical bolting and riveting of aluminum alloy structures. Laser welding is a promising solution. The difficulties encountered in light alloys welding process justify the recent innovations in laser design aiming better performance and good quality welds. Appearance of defects such as porosities, hot cracking, loss of alloying elements by vaporization etc. in welded assemblies is one of the major issues with this process. So, a number of serious critical aspects need to be considered. Further research is therefore needed to improve construction in aluminum alloys. This thesis focused on the Yb: YAG laser welding of AA6061-T4 aluminum alloy thin sheets. The first part of this study allowed the determination of the weldability range of the 1 mm thick alloy AA6061-T4 butt welded by laser beam Yb: YAG, without filler metal. The samples are welded using two fiber configurations. The influence of the fiber configuration and of the main welding parameters on the bead's geometric characteristics and the magnitude of weld defects was studied. Metallurgy and mechanical properties of optimized welds have been characterized at different scales. This study was carried out within the different areas of the weld. The results are then interpreted according to energetic parameters of the process. The corrosion behaviour study of four welds, chosen from the weldability range, showed the absence of macroscopic galvanic couplings between the different zones of the welds. It was also demonstrated, for the first time on this system, the existence, in the as-welded state, of a "sensitized zone”, characterized by a form of intergranular corrosion. Moreover, a T6 thermal post-treatment seems to have a strong influence on the system behaviour by removing the localization of the previous “sensitized zone”. The AFM / KFM technique has proven to be a cutting-edge technique for studying local surface potentials and thus characterizing the corrosion mechanisms at the sub-micrometric scale
Étude d'un alliage d'aluminium pour l'aéronautique par les techniques avancées de microscopie électronique en transmission by Marion Le Fournier( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

In aeronautics, structural hardening is one of the best ways to improve mechanical properties of metal alloys and to make the structures lighter. The structural hardening of the Al-Li-Cu alloys of the 2000 series is due to T1 precipitates (Al2CuLi) which modify locally the matrix which surround them. To understand the mechanism of deformation at a micro scale, we need to know the interactions between dislocations and hardening phases. Consequently, a precise characterization of strains is required. To do that, experimental techniques, which are supported by models, have been developed. Using high resolution electronic transmission microscopy (HREM) and geometrical phase analysis (GPA), a method is proposed to measure strains in three directions of the space. Then, the precipitates were modeled by two dissociated dislocations which are perfectly identified as a/6<112>. The growth mechanism of T1 phases is based on the presence of these dislocations. Other models have been developed to reproduce the strains created in the matrix by the precipitate. They are based on the dislocation theory and the resolution of the equations of micromechanics in the reciprocal space using isotropic and linear elasticity. By employing those models, we are able to propose a description of the strains near the tips of precipitates which is in agreement with the HREM observations
Structure fine des dislocations et plasticité dans NiAl by Joël Douin( Book )

1 edition published in 1987 in French and held by 1 WorldCat member library worldwide

 
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Interfaces and plasticity : proceedings of the Advanced School Meeting 'Dislocations 96' held in Tozeur, Tunisia, October 1996 = Interfaces et plasticité
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