Дисертації з теми "Mécanismes de recristallisation"
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Kiaei, Mercedeh. "Etude des mécanismes de recristallisation dans des aciers bas carbone." Paris 13, 1996. http://www.theses.fr/1996PA132018.
Повний текст джерелаJakani, Saâd. "Effet des impuretés sur les mécanismes de recristallisation du cuivre tréfilé." Phd thesis, Université Paris Sud - Paris XI, 2004. http://tel.archives-ouvertes.fr/tel-00220406.
Повний текст джерелаWang, Wei. "Etude des mécanismes de recristallisation de nouveaux alliages à base de Ni." Phd thesis, Université Paris Sud - Paris XI, 2014. http://tel.archives-ouvertes.fr/tel-01024285.
Повний текст джерелаZhu, Kangying. "Etude des mécanismes de déformation et de recristallisation dans un alliage de zirconium." Paris 13, 2006. http://www.theses.fr/2006PA132021.
Повний текст джерелаGourdet, Sophie. "Étude des mécanismes de recristallisation au cours de la déformation a chaud de l'aluminium." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 1997. http://tel.archives-ouvertes.fr/tel-00783855.
Повний текст джерелаGourdet, Sophie. "Étude des mécanismes de recristallisation au cours de la déformation à chaud de l'aluminium." Grenoble INPG, 1997. http://www.theses.fr/1997INPG4206.
Повний текст джерелаKerisit, Christophe. "Analyse des mécanismes de recristallisation statique du tantale déformé à froid pour une modélisation en champ moyen." Phd thesis, Ecole Nationale Supérieure des Mines de Paris, 2012. http://pastel.archives-ouvertes.fr/pastel-00873188.
Повний текст джерелаGerber, Philippe. "Etude des liens entre hétérogénéités de déformation et mécanismes de recristallisation. Application au cuivre et ses alliages." Paris 13, 2002. http://www.theses.fr/2002PA132027.
Повний текст джерелаThe study of the relation between deformed inhomogeneities and static recrystallization is done in copper and -brass in cooper, a critic value of deformation (cold rolling to =90 %) is obtained from the bulk texture analysis. Below this value, the recrystallization texture {100}<001>is obtained. In x-brass, the deformation texture is even more complicated due to the deformation twinning mechanisms, which conducted to a weaker texture. The comparison of the experimental measurements in copper for two levels of reduction ( =70 % and =90 %) is done in order to understand the influence of the deformed state on recrystallization. Stored energy measurements show that minimum difference is needed between the C {112}<111>and/or S {123}<634>and the Cube orientations to produce the Cube texture. For both materials, a recovery of the Cube grains is observed. From EBSD measurements in copper =70 %, intergranular nucleation takes place in highly deformed regions, which conducts to a dispersed texture. In copper =90 %, this nucleation is not the main mechanism. Indeed, after recovery inside Cube/G {011}<100> transition bands, a fast process of nucleation and growth of the Cube orientation is observed. This corresponds to the oriented nucleation and growth hypothesis. In copper, Monte-Carlo simulation is used in order to explain the recrystallization texture after cold rolling to =70%. The experimental recrystallization texture is difficult to obtain, and this can be due to the annealing twinning active nucleation and growth steps
Moreno, Marc. "Mécanismes métallurgiques et leurs interactions au recuit d’aciers ferrito-perlitiques laminés : caractérisation et modélisation." Thesis, Université de Lorraine, 2019. http://www.theses.fr/2019LORR0068.
Повний текст джерелаFerrite/Martensite Dual-Phase steels are largely used in the form of thin sheets in the automotive industry for their excellent balance between resistance and strength and thus for their lightening potential. They are elaborated by continuous casting, hot- and cold- rolling, followed by a continuous annealing. During the heating and the soaking stages of this latter process, the deformed ferrite/pearlite microstructure obtained after rolling evolves is transformed into a recrystallized ferrite-austenite microstructure. The experiments show that recrystallization and austenite transformation kinetics as well as the resulting spatial and morphological distribution of the phases are highly sensitive to the heating rate. This PhD thesis aims at understanding the different metallurgical mechanisms explaining this particular sensitivity as carbides ripening, recovery, recrystallization and austenite transformation and all their possible interactions. The mechanisms were characterized at different scales and by in situ technics on an industrial steel and model by physical based approaches in order to drive future production lines. After a first chapter dedicated to the experimental and modeling methods, the second chapter deals with the characterization of the morphogenesis of ferrite-austenite microstructures by Scanning Electron Microscopy (SEM). Chapter 3 is a study by Transmission Electron Microscopy (TEM) and by thermokinetic modeling (ThermoCalc, DICTRA) of the chemical composition of carbides along with manufacturing, from hot-rolling to annealing. Recovery and recrystallization are studied in chapter 4 by the means of in situ High Energy X-Ray Diffraction (HEXRD) experiments conducted on a synchrotron beamline and modeled by an original mean-field approach. Finally, chapter 5 proposes an analysis with DICTRA to understand austenite transformation kinetics as function of heating rates. The proposed approach is innovative as it accounts for intergranular carbides in the ferrite matrix, is conducted in non-isothermal conditions and propose a fine analysis of growth modes of austenite associated to manganese, a key alloying element of the studied steels
Samet-Meziou, Amel. "Etude des mécanismes de recristallisation dans un acier IF-Ti après faible déformation par laminage ou par traction." Paris 11, 2005. http://www.theses.fr/2005PA112010.
Повний текст джерелаThis work permit to establish a relation between the substructures of deformation of an IF-Ti deformed by rolling (40%) or tensile strain (35%) and the recrystallization mechanisms. With this intention, the substructure of deformation was characterized by transmission electronic microscopy for the three principals components of the deformation texture: the {111}<112> orientation of the fiber and the {111}<110> and {001}<110> orientations of the fiber. Two types of substructures were observed: lamellar bands for the {111}<112> grains and equiaxed cells for the grains of the fiber. This characterization of the deformed state was completed by an estimation of the stored energy using various approaches (neutrons diffraction, EBSD, TEM) and showed the following hierarchy: E{111}<112 > > E{111}<110 > E{001}<110 >. The first stage of annealing is characterized by recovery. This process is assumed by: refinement of the walls of cells, the vanishing of dislocations inside the cells, the coalescence and growth of the cells. The cellular substructure is most favourable to the growth. For the two observed substructures, a sufficient size is necessary to ensure the formation of a viable nucleus. The formation of recrystallized grains is ensured by two mechanisms: generalized recovery mainly observed for the substructure of lamellar bands and the "Bulging" specific to the équiaxes substructures
Jedrychowski, Mariusz. "Etude expérimentale et modélisation des mécanismes de recristallisation et de la croissance de grains dans des métaux de structure hexagonale." Thesis, Paris 13, 2014. http://www.theses.fr/2014PA132058/document.
Повний текст джерелаThe main aim of this thesis is to describe and analyse recrystallization and grain growth phenomena taking place in hexagonal metals, in particular cold-rolled titanium and channel-die compressed zirconium were considered. For that reason, several experiements were prepared and carried out using EBSD (Electron Backstartter Diffraction) technique. In addition, a special software based on Monte Carlo Potts model was developed in order to facilitate experiemental analysis using simulation approach. Based on the obtained experiemental data and simulation results, physical models and hypotheses concerning the investigate recrystallization and grain growth processes were proposed and positively verified
Mallick, Robin. "Effet des traitements thermomécaniques sur la microstructure d'un alliage de titane Ti2AlNb." Electronic Thesis or Diss., Université Paris sciences et lettres, 2022. http://www.theses.fr/2022UPSLM078.
Повний текст джерелаDue to their excellent properties, especially, high temperature mechanical strength and low density, Ti2AlNb-based alloys are considered as promising materials for rotating parts in aircraft engines. Such properties are obtained through appropriate thermomechanical treatment which should result in optimal microstructure for a specific application. Different stages of thermomechanical treatments of Ti2AlNb alloys are still required to be optimized to guarantee the best alloys performance. Therefore, the understanding of microstructure evolution of Ti2AlNb alloys during high temperature processing is of particular industrial interest.The aim of the present work was to investigate the microstructure changes in a Ti2AlNb alloy induced by high temperature plastic deformation in the temperature range of 1010-1204 °C, in order to further optimize high temperature alloy processing. The dynamic evolution of the microstructure was analysed through compression and torsion tests followed by quenching, and hot extrusion tests were used to generate a first stage of post-dynamic recrystallization of the alloy. Finally, post-deformation isothermal heat treatments were used to study the static recrystallization phenomenon. The microstructure was characterized by means of optical microscopy and electron backscatter diffraction (EBSD) in scanning electron microscope. The effect of high-temperature deformation parameters on the microstructure evolution was studied. It is revealed that continuous dynamic recrystallization leads to the formation of a low volume fraction of recrystallized grains in the area close to the initial grain boundaries. Some of these grains will further become nuclei for post-dynamic or static recrystallization. Post-deformation isothermal heat treatments allowed to study the kinetics of static recrystallization and to investigate the effect of initial grain size, temperature and strain rate
Thebault, Julien. "Etudes expérimentale et numérique des mécanismes de déformation et de recristallisation de l'UDIMET 720 lors du forgeage. Relations entre la microstructure et la perméabilité aux ultrasons." Thesis, Châtenay-Malabry, Ecole centrale de Paris, 2009. http://www.theses.fr/2009ECAP0037.
Повний текст джерелаThis works deals with the correlations between the thermomechanical process, the microstructure and the permeability to ultrasonic waves of the Udimet 720 superalloy. The first approach is experimental and concerns the influence of the thermomechanical parameters (temperature, strain rate and deformation ratio) on the microstructure evolution. In particular, this study focuses on the identification of recrystallization mechanisms. In parallel, a mesoscopic crystalline modelling of deformation implemented in a finite element code coupled to a recrystallization Cellular Automaton code has been developed and applied to forging processes. The model predicts the evolution of different experimental microstructures as a function of thermomechanical parameters.The last part deals with the identification of unfavorable parameters of the microstructure on the ultrasonic permeation. Moreover a modeling of the ultrasounds propagation in a polycrystalline material is proposed to quantify the effects of the average grain size and the grain misorientation distribution
Philippot, Clément. "Etude des mécanismes de précipitation, de recristallisation et de transformation de phases dans les aciers Dual Phase microalliés au titane niobium lors du recuit." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4342.
Повний текст джерелаLightening the weight of vehicles is one of the main challenging objectives of the automotive industry to reach the environmental regulation in term of CO2 emissions. The development of multiphase high strength steels is a common solution to reduce the thickness of sheet steel used in vehicles while keeping the same level of passenger’s safety requirements. The present study deals with the optimization of industrial process parameters applied to obtain one of these steels: the high strength microalloyed Dual Phase steels; i.e. with ultimate tensile strength superior to 800MPa.From an initial cold rolled microstructure made of bainite + martensite, the phenomena occurring during the annealing are characterized since the heating up to the end of the intercritical holding. The influence of process parameters as the heating rate, the holding temperature and the holding time are studied. The triple interactions system between the precipitation of microalloying elements, the recrystallization and the austenite formation is the core of the problem. A scenario of microstructural evolutions has been established based on the characterized phenomena. The studied fine microstructure (sub-microns) requires the combination of multiscale characterization techniques: SEM, TEM, atom probe tomography, nano-SIMS
Painchaud, Thomas. "Mécanismes de croissance des couches minces de Cu (In, GA) Se2 co-évaporées : vers des synthèses rapides et à basse température." Nantes, 2010. http://www.theses.fr/2010NANT2088.
Повний текст джерелаCu(In1-xGax)Se2 solar cells are based on the Mo/Cu(In1-xGax)Se2/CdS/i-ZnO/ZnO:Al structure. Therapid growth of co-evaporated CIGSe thin films at low temperature is an important issue for theindustrial development of CIGSe modules. In order to achieve these 2 targets, CIGSe growthmechanisms during the 3-step process have been investigated. In the present work, a recrystallizationphenomenon has been underlined when the copper content within the CIGSe (0 ≤ x ≤ 0. 3) reaches the stoechiometry, i. E. Y = [Cu]/([In]+[Ga]) ≈ 1. Such a phenomenon is thermally activated and results in the reduction of both the grain boundaries (GB) density and intra-granular defects density. From these observations, a new model based on the grain boundary migration theory is proposed in order to establish a causality relationship between such a composition threshold and the grain boundary motion yielding large grains formation. The understanding of this mechanism allowed the decrease of the deposition time of co-evaporated layers from 23 min (h=16%, FF=76%) to 6 min (h=14%, FF=74%)at Tsub= 600 °C. Within the 3-step process, the homogenous composition of the absorber seemsrestricted by the high speed deposition during the 3rd step. Finally, in order to decrease the substratetemperature, the impact of Mo back contact has been investigated. The sodium diffusion from the glass substrate into CIGSe across the Mo plays an electronical role and is influenced by themolybdenum porosity and Tsub. The experimental optimization of the Mo back contact has allowed the achievement of 13. 5% efficiency with CIGSe absorber synthesized at Tsub = 450°C