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Amri, Boudjemaa. "Contribution à l’étude du comportement des matériaux modernes pour les outils coupants". Lyon, INSA, 1988. http://www.theses.fr/1987ISAL0069.
Pełny tekst źródłaGrunder, Timothee. "Contribution à l'application de céramiques d'Al2O3 et de 3Y-ZrO2 à structures submicroniques à l'usinage de matériaux dérivés du bois". Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAD035.
Pełny tekst źródłaHigh mechanical properties of sub-μm grain Al2O3 and 3Y-ZrO2 present high potential for the cutting of wood-based materials. Nine grades were produced by gelcasting (GC) and cold isostatic pressing (CIP). They were tested in real industrial conditions. From those results, this thesis’ aim was to highlight the wear mechanisms in cutting, and then deduce major physical and mechanical properties that are task of material development. Consequently, prototypes for cutting trials have been developed. As a result, the manufacturing of prototype tools, X-Ray diffraction, analytical and numerical investigations were performed to quantify residual stress that occurred in ceramic. Observation of the results of experimentations in machining showed different wear modes. For alumina’s grade, single grain pull-out was the main wear mechanism of the cutting edge, while microplastic deformation occurred in zirconia’s composition. Physical properties of ceramic structure, like grain size and density, are more important than mechanical properties. To improve cutting lifetime, density must be higher than 99%, with a structure with sub-μm grain size. It appeared that there was a predominant role of micromechanical stability while cutting abrasive materials. Fracture toughness or thermal shock resistance seem to have marginal influence when ceramic were produced by low-defect process like GC. Regarding all ceramic grades the Al2O3-10ZrO2 made by GC showed the highest wear resistance in machining. Unstabilized zirconia brought micromechanical stability between grains of the cutting edge while working
Gilles, Patrick. "Positionnement d'outil torique pour l'usinage de surfaces gauches en fraisage 5-axes avec équilibrage de l'effort de coupe transversale". Toulouse 3, 2008. http://thesesups.ups-tlse.fr/330/.
Pełny tekst źródłaThe presented work consists to improve milling process of sculptured surfaces. The aim is to reduce disturbances during machining in order to obtain a better surface roughness without increasing the manufacturing time. The study was conducted in 5-axis milling for torus cutter with round inserts suitable for the considered parts. The first part of this study establishes a cutting force model with a tool axis inclination towards the back of the tool. It leads to a formulation to balance the transversal cutting force that brings a significant improvement on tool dynamic behaviour. The second part presents a free gouging tool positioning and an associated strategy using the balance of transversal cutting force. The proposed method is globally validated on a complete example of sculptured surface machining
Thil, Julien. "Contribution à l'étude expérimentale et à la modélisation de l'usinage des matériaux difficiles pour le procéde de forage profond avec système BTA". Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0211/document.
Pełny tekst źródłaDeep drilling (Drilling distance >= 5 x Øtool) with BTA system (Boring Trepanning Association) occurs when you produce parts with good productive performance combined with good machining quality. Mechanical industries operate in a context of constant competition, with ever greater technical and economic requirements. This study illustrates the desire of many industrial players (AREVA and CIRTES) and university (LEMTA, Université de Lorraine), to advance in the understanding of machining mechanisms that govern this process. A literature review revealed that this technology offers a vast and relatively unexplored field of investigation and study. The aim of this study is to analyze and modelling the phenomena which occurring in a deep drilling operation. An analysis of the morphology of the chips has introduced a new parameter for assessing the mechanical stresses suffered by the material being machined . The proposed approach allows to define the mechanical stress torsor by integrating the real cutting geometry, for all cut surfaces of active drilling head BTA. The principles of modeling used allow a relatively easy application to many materials and from the identification of a minimum parameters. Original experimental methods have allowed the identification of parameters and adjust and examine the validity of modeling. The limitations of the law of behavior have been used in evidence, and the prospects for further studies have been proposed. Nevertheless, all the results of this study open, modestly, interesting perspectives, especially in the field of helping for the choice of optimum cutting parameters, and help in the understanding of the physical phenomena of the cut
Agode, Kofi Edoh. "Analyse et modélisation du comportement à l’usure des outils de coupe en carbure de tungstène pour différentes teneurs en cobalt lors de l’usinage de l’alliage de titane Ti-6Al-4V". Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0141.
Pełny tekst źródłaDue to their high hardness and wear resistance, cemented carbide (WC-Co) is the main material used to manufacture machining tools and forming tooling, as well as wear parts requiring high hardness and high precision. The modification of tungsten carbide microstructure, and more particularly its cobalt content, is currently attracting the greatest interest from manufacturers to develop new grades tools with high performance, and then expand new markets.This thesis aims to study the effect of the cobalt content of carbide tools on the measured values and wear mechanisms when machining hard superalloys such as the aeronautical titanium alloys Ti-6Al-4V. Both experimental and numerical research work are devoted on one hand to the understanding of the microscopic damage mechanisms leading to the macroscopic wear of the WC-Co composite and on the other hand, to the influence of the cobalt content on the behavior of the WC-Co taking into account the mechanical-microstructure-damage coupling.On the basis of an experimental analysis, the identification of the macroscopic and microscopic physical phenomena involved at the tool/chip and tool/workpiece contact interfaces was conducted. Machining tests were firstly carried out on the tool-material couple WC-Co/Ti-6Al-4V with different cobalt contents for the tools (from 6 to 15%). In a second step, a tribological characterization of the same tool-material couple was carried out to evaluate the influence of the cobalt content and the contact conditions (sliding speed, applied force) on the friction coefficient and wear. However, the inaccessibility of the contact zones during machining and the tribological tests did not allow a complete description of the wear mechanisms observed, whether macroscopic mechanisms (adhesion, abrasion, deformation, ...), or microscopic mechanisms (cracking, damage of the WC and Co phases). The numerical simulation using finite elements (FE) proved to be a very interesting complementary tool for the analysis of these wear mechanisms.Our modeling strategy focused on the response of WC-Co at the microstructure scale for the thermomechanical loading close to that obtained by machining. The proposed model takes into account the behavior of the WC and Co phases separately and that of the interfaces WC-WC and WC-Co of the composite. This strategy allowed to study and identify parameters influencing the behavior of the microstructure from the elastic stage to the damage initiation. A good agreement was obtained between the results of the numerical behavior at the initiation of damage in the microstructure and those of the experimental observations in terms of the effects of the cobalt content in the tungsten carbide and of the applied machining conditions
Morandeau, Antoine. "Méthodologie de caractérisation et de conception d'un outil coupant à plaquettes amovibles pour l'usinage de matériaux composites aéronautiques : Application aux opérations de surfaçage". Thesis, Tours, 2012. http://www.theses.fr/2012TOUR4041/document.
Pełny tekst źródłaAeronautic composites are inhomogeneous and most often consist in two distinctly phases. The reinforcement fibres are relatively hard and brittle whereas the matrix is soft and ductile. The anisotropy causes some severe challenges when machining composites. People in the field often experience a trade-off between two main problems ; on one hand, keeping the composite parts integrity and quality, and on the other hand, reducing the wear of the cutting tools. The quality level required in aeronautic applications imposes a high quality cut of machined parts. Common defects that may occur during machining of these materials are delamination, overheat of the resin, uncut fibres, and fibre pull-out
Segreti, Michel. "Vibrations en coupe orthogonale : Modélisation, étude de stabilité et validation expérimentale". Metz, 2002. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2002/Segreti.Michel.SMZ0201.pdf.
Pełny tekst źródłaPantalé, Olivier. "Modélisation et simulation tridimensionnelles de la coupe des métaux". Bordeaux 1, 1996. http://www.theses.fr/1996BOR10620.
Pełny tekst źródłaCherif, Mehdi. "Modélisation générique des efforts de coupe en fraisage pour la CFAO et la surveillance de l'usinage". Nantes, 2003. http://www.theses.fr/2003NANT2090.
Pełny tekst źródłaGoldschmidt, Ephraïm James Martin. "Gammes et cotation pour le réglage des machines-outils de décolletage". Chambéry, 2009. https://tel.archives-ouvertes.fr/tel-01053861.
Pełny tekst źródłaProduction equipment has undergone significant technical developments in recent decades. The current trend is to minimize the number of setups required to machine a part in order to improve the cycle lime and accuracy. The screw rnachining industry is heavily subject to the problem of meeting increasing production volumes under stronger customer requirements. Unfortunately, methodological tools and software packages have not evolved at the same pace and the indus-trialization of parts of increasing complexity remains a serious problem. However, "academic" in- dustrialization methods do exist, but they were initially designed for conventional part machining out of plots of material and are not adequate when machining parts out of bars, which is the main characteristic of screw machining. The flow method presented in this thesis tackles this problem by providing a systematic approach to the methods technicians, enabling them to sequence the different manufacturing operations into a minimum number of steps and thus; a minimum number of machine halts. To do so, we propose a formal description of the manufacturing process, organizing it in work stations, setups and manufacturing operations. We then propose to organize the manufacturing operations in steps intended either for the initial or periodical setting up of machines, or for their monitoring in production. The creation of a different setting up plan than the monitoring plan seems essential and is consistent with the fact that the setting up and monitoring of machines are often carried out by two different persons in industry, in this case, a setter and an operator. For each of the plans, we determine a set of working dimensions through an innovative approach called the "chain of dimensions of minimal measurement uncertainty". To this set of working dimensions, we propose to add a new set of dimensions that we call "pilot dimensions". These correspond to the parameters on which the operators can act upon in order to correct working dimension deviations. A spreadsheet is then generated for the operator. This spreadsheet will provide the operator with the corrections that need to be carried out on the pilot dimensions based on the deviations measured from the working dimensions for each step of the setting up or monitoring process. Experiments on industrial cases have helped us to validate our approach which has been implemented in an industrialization software package called Copilot Pro®. This research program is the result of the collaboration between the SYMME laboratory of the “Université de Savoie” and the “Centre Technique de l'industrie du Décolletage”, and is also part of the “Tolérancement et Qualité des produits” program of the “Pôle de Compétitivité Arve-Industries Haute-Savoie Mont-Blanc”
Simonin, Guillaume. "Améliorations des performances d'outils de coupe pour la première transformation du bois". Thesis, Nancy 1, 2010. http://www.theses.fr/2010NAN10117/document.
Pełny tekst źródłaSIAT-BRAUN is the largest industrial sawmill in France and faces typical industrial challenges with its sawing technologies.Wood saws must be as thin as possible, in order to maximize yield and save raw material and robust enough to endure tougher and tougher sawing conditions. Good raw material control and optimized machine parameterization are critical to ensure good results. The current theoretical background, does not always match these requirements and we are therefore always testing its limits.An economical and technical analysis of the sawmill and its evolution makes up the first part of this thesis. We will be detailing the key operations of one of the most modern sawmill in Europe.Current knowledge analysis must include the various parameters and calculations necessary to machine wood, as well as the different blade components and their geometric specifications. We will discuss the interactions between these elements. The job of the filer (the person in charge of tool maintenance) will also be discussed, as well as several improvements implemented in the workshop.Many improvements have been suggested and implemented while working on this thesis, in order to react to production needs while preserving reliability. In the last section of this thesis we will discuss several improvements that remain to be validated on how to best match appropriate cutting materials and blade geometry
Nouari, Mohammed. "Modélisation de l'usure par diffusion des outils de coupe en usinage à grande vitesse". Metz, 2000. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2000/Nouari.Mohammed.SMZ0039.pdf.
Pełny tekst źródłaLarue, Arnaud. "Prise en compte des déformations d'un outil dans le calcul des trajectoires d'usinage en fraisage de profil". Cachan, Ecole normale supérieure, 2003. http://www.theses.fr/2003DENS0017.
Pełny tekst źródłaGaudillière, Camille. "Cisaillage à grande vitesse : des essais à la simulation". Paris, ENSAM, 2011. http://www.theses.fr/2011ENAM0052.
Pełny tekst źródłaTo increase their productivity, blanking professionals are interested by an emerging process: the high speed blanking. For this process, the punch speed reaches10m/s whereas this speed does not exceed 0,1m/s for conventional blanking process. However, even if the quality of the obtained surfaces is close to those obtained with fine blanking, the occurence of hard dynamic phenomena makes difficult the deployment of the high speed blanking process. This work proposes to better control this process using experimentations and numerical simulations. An instrumented device has been designed to observe in detail the existing phenomenon during cutting. This device is similar to the industrial one. It includes a punch with non-constant sections and a matrix linked to an Hopkinson's tube in order to measure the blanking cutting forces. This measure requires a specific treatment to correct dynamic effects present in the matrix during the cutting. This treatment, which uses a calibration of the device, was validated thanks to a one-dimensional numerical model. Many observations made on the blanked surfaces have shown that adiabatic shear bands (ASB) can take place. A thermo-mechanical constitutive model (Johnson-Cook's law) of the C40 steel has been identified and used into simulations to reproduce real experimentations. The used simulation is based on a C-NEM approach (Constrained Natural Element Method). A comparative study between simulation and experimental results has been done. Results show a good correlation with experimental tests
He, Jianguo. "Modélisation des flux d'informations liées aux outils coupants : développement de méthodologies et d'outils de gestion adaptés". Lyon, INSA, 1991. http://www.theses.fr/1991ISAL0074.
Pełny tekst źródłaAt a time when quality and profitability have become the main demands regarding the production apparatus, increasing interest has arisen for tool management, which appears as one of the major keys to achieve these goals. A tool management methodology has been developed in this paper. It mainly deals with : the analysis of all the activities linked with tool management and t he structuration of the necessary pieces of information, - the building up of the functional relationships between the database entities, as well as of a tool codification system, - the modelisation of the tasks and the Logical relations of tool management, - the dynamic tool flow simulation, taking the Laws into account , which describe tool failure probability, - the development of several tool replacement strategies based on the stochastic nature of tool lite and their validation through simulation, the elaboration of a basic module for technical and economie calculation and the output of which are indicators enabling the user to appraise the performance of the tool management system
Rougié, Alexandre. "Analyse et conception d'un outil de coupe pour la valorisation des sous produits d'élagage des haies : démarche intégrée d'innovation et de prototypage". Thesis, Nancy 1, 2009. http://www.theses.fr/2009NAN10045/document.
Pełny tekst źródłaNOREMAT is specialized in the manufacturing of equipments for the maintenance of road verges. Its issue is to continuously propose profitable equipments to its customers. The company also wishes to design, thanks to scientific research, a new trimming concept offering more cost-efficient and ecological solutions. After a series of preliminary steps (analysis of French hedges, waste valorization options, design suggestion, analysis of trimming phenomena), a prototype was designed. This new tool fulfills three major functions: it cuts hedges economically and safely, it crushes the wastes into heating chips and collects them. Based upon the study of chips formation and the control of cutting parameters during the branches processing, this new tool offers a better trimming in comparison with the existing devices, while requiring less energy, adding value to waste products and protecting its surrounding area. Regarding scientific contribution, these researches have lead to a better understanding of the chip’s building up in the specific case of flexible elements trimming
Halila, Faycel. "Modélisation analytique et caractérisation expérimentale de l'usure par abrasion des outils de coupe". Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0147/document.
Pełny tekst źródłaTool wear and tool failure are critical problems in the industrial manufacturing field since they affect the quality of the machined workpiece (unexpected surface finish or dimensional tolerance) and raise the production cost. Improving our knowledge of wear mechanisms and capabilities of wear prediction are therefore of great importance in machining. The three main wear modes usually identified at the tool/chip and the tool/workpiece interfaces are abrasion, adhesion and diffusion. Besides the fact that understanding mechanisms that govern these wear mechanisms are still incomplete, the experimental analysis is very difficult because friction interface features (such as temperature, pressure, particles embedded in the contact …) are not easily measurable. The objective of this research work is to understand the physical mechanisms governing the tool wear by taking into account the sensibilities to scale going from the microscopic scale (microstructure scale) to the macroscopic scale (scale of the manufacturing operation) passing by the mesoscopic scale (tool tip scale). For this purpose, an analytic wear model was developed to describe the abrasive wear and to predict the cutting tool life. The proposed model is based on a tribological approach including a statistical description of the distribution of particles seen as non-metallic inclusions. The latter are assumed embedded at the interface of contact and having a conical shape characterized by two main parameters in the present approach: the corresponding size and apex angle. The volume of the removed material per unit time is chosen in this study as the main parameter to describe the abrasive wear mode. Coupled with literature results, the developed model is able to take into account the nature of the sticking-sliding contact and the effect of the friction coefficient on the rake face of the cutting tool. In order to identify all the material's parameters of the predictive model, a study of non-metallic inclusion considered responsible of the abrasive wear was performed on the 42CD4 steel. The determination of inclusion type and inclusion morphology was assessed qualitatively and quantitatively through microscopic and MEB observations as well as image processing. Finally, the volume removed by abrasion given by the model was compared to the experimental results previously achieved under orthogonal cutting
Ait, Sghir Khalid. "Contribution de la cyclostationnarité et de l'identification aveugle au diagnostic des outils de coupe". Thesis, Saint-Etienne, 2010. http://www.theses.fr/2010STET4012.
Pełny tekst źródłaThe identification of the state of a cutting tool is important in any metal cutting process. An additional cost - in terms of scrapped components, machine tool breakage and unscheduled downtime - occurs as a result of tool defects. The thesis objective is the cutting tool vibration analysis of a milling operation for the diagnosis of their state of degradation. In the first part, the possibilities offered by the synchronous statistics, applied to vibration signal captured from a milling process, are studied to examine the cutting tool condition. The processed vibration signals are cyclostationary, i.e their statistical properties are periodic. Taking into account this property, the use of descriptors able to characterize the process, in conjunction with the kinematics of the mechanical machining operation. Furthermore, when combined with the angular sampling, the cyclostationarity led to the proposed synchronous statistical estimators convenient to implement. First order and second order synchronous statistics, the spectral correlation and the cyclic bispectrum are defined with their interpretations and estimators. A model of milling vibration signal is given. This model aims to demonstrate the cyclostationarity of the signals. The use of these indicators is illustrated on real signals and compared with conventional indicators for diagnosing degradation of cutting tools.In the second part, the blind deconvolution of the impulse response of a cyclostationary process is
Aguilera, León Alfredo Armando. "Optimisation des conditions de coupe pour l'usinage du bois : application de la méthode Couple Outil Matière au défonçage des panneaux de fibres de densité moyenne". Nancy 1, 2000. http://docnum.univ-lorraine.fr/public/SCD_T_2000_0002_AGUILERA.pdf.
Pełny tekst źródłaBen, Younes Jalel. "Modélisation des ressources en fabrication mécanique : application au choix des outils coupants dans un environnement orienté objet". Châtenay-Malabry, Ecole centrale de Paris, 1994. http://www.theses.fr/1994ECAP0327.
Pełny tekst źródłaDalloz, Alexandre. "Etude de l’endommagement par la découpe des aciers dual phase pour application automobile". Paris, ENMP, 2007. http://www.theses.fr/2007ENMP1502.
Pełny tekst źródłaIn order to optimize the metallurgical quality of future dual phase steels, the present study aims at a better understanding of the formation of the cut edge damage induced by shearing. Observations and characterizations revealed the existence of a highly deformed area in the vicinity of the cut edges. This region of 200 µm is defined as the cutting affected zone. In addition to deformation, its microstructure presents voids, initiated at ferrite-martensite boundaries. The formation of this zone during the cutting process was studied through two complementary approaches: first, the use of an especially designed testing device that allows precise interruption of the cutting process, then, the simulation of the process by finite elements methods. The damage and the fracture of the sheets appeared to be controlled by the voids formation at the phases boundaries and thus by the stress triaxiality ratio. The study of the cut edge behaviour under loading showed the rapid initiation of small cracks in the cutting affected zone. The direct impact of these cracks on the sheets ductility was also highlighted. Finally, two heat treatments that limit the ductility loss induced by cutting were proposed: one by the formation of a third phase during cooling and the other by offering better mechanical properties around phases boundaries
Kagnaya, Tchadja. "Contribution à l’identification des mécanismes d’usure en usinage d’un WC-6%Co par une approche tribologique et thermique". Paris, ENMP, 2009. http://pastel.archives-ouvertes.fr/pastel-00005750.
Pełny tekst źródłaThe aim of this work is to study wear mechanisms of WC-6%Co cutting-tools in machining by turning. Damage modes are controlled by complex damage mechanisms. They combine abrasion, adhesion and diffusion. Furthermore, they are highly dependant of the temperature levels at tool/material interfaces. In the present study two mains approaches are considered: on the one hand machining by turning and on the other hand tribological tests. In both cases temperature measurements and temperature modelling have been performed. Complementary results have been obtained, resulting in a better understanding of wear behaviour between WC-6%Co and a C45 steel grade. Mains wear mechanisms were identified. They deal with: - large modifications of the WC-6%Co microstructure due to critical mechanical loadings and to high temperature levels (up to 1200°C), - mobility of WC grains due to the viscoplastic behaviour of the cobalt based binder phase at high temperature. Such a mobility leads to intergranular microcracking phenomena and to WC fragmentation and debonding mechanisms, - intragranular microcracking and strain phenomena, that can lead to WC grain fragmentation, due to stress concentrations, - abrasion due to extracted WC fragments and to hard particules extracted from the C45 steel too, - adhesion, particularly at the end of the contact area between tool and chip
Chanal, Hélène. "Etude de l'emploi des machines outils à structure parallèle en usinage". Phd thesis, Clermont-Ferrand 2, 2006. https://theses.hal.science/docs/00/69/85/32/PDF/2006CLF21673.pdf.
Pełny tekst źródłaChanal, Hélène. "Etude de l'emploi des machines outils à structure parallèle en usinage". Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2006. http://tel.archives-ouvertes.fr/tel-00698532.
Pełny tekst źródłaHaddouche, Kamel. "Apports d'automatique avancée dans la conduite d'un usinage". Bordeaux 1, 1995. http://www.theses.fr/1995BOR10545.
Pełny tekst źródłaBranci, Samy. "Traitement d'un signal acoustique : application au mécanisme d'abrasion de la meule". Montpellier 2, 1995. http://www.theses.fr/1995MON20077.
Pełny tekst źródłaCastro, Martinez Luis Ricardo. "Identification des sources de vibration en usinage : étude expérimentale et numérique". Metz, 2006. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2006/Castro_Martinez.Luis_Ricardo.SMZ0624.pdf.
Pełny tekst źródłaThe main objective of this project is furnishing information to clarify the vibrations physics in machining from orthogonal cutting. First chapter contains the machining process characterisation by means of cutting forces. We evaluate the piezoelectric dynamometers in frequency domain and the influence of assembly components. These evaluations reveal the dynamic measurements problems. At the end of this part, we propose a correction method of piezoelectric dynamometer measurements to frequencies higher than dynamometer bandwidth. Also, we present an application of the method. Second chapter comprises the understanding of vibration sources. We analyse specially the segmented chip formation because its excitation role is not clear in literature. Also, we consider the effects of regenerative excitations, which depend of interaction between cutting conditions and machine-tool dynamic response. Third chapter includes the experimental identification of vibration sources during machining. We have identified and characterized the segmented chip formation and the machine-tool dynamic
Pagès, Christian. "Comportement de revêtements céramiques sur outil en tournage de finition à sec". Ecully, Ecole centrale de Lyon, 2003. http://bibli.ec-lyon.fr/exl-doc/cpages.pdf.
Pełny tekst źródłaThis work has been carried out in Laboratoire de Tribologie et Dynamique des Systèmes (LTDS UMR 5513) at Ecole Nationale d'ingénieurs de Saint-Etienne (ENISE) in collaboration with BLAZERS corporation which provided cutting tools ceramic coatings (AIN - TiN). The aim of this work is to understand these different coatings behaviour during dry finishing hard turning. In first time, we identified the main factors influencing the coatings behaviour and the parameters to study in order to define the coatings damage. Active factors being : cutting speed, feed, depth of cut and workpiece material. The damage parameters being : cutting edge evolution, cutting wear incise, cutting power and loading, surface quality, shape, volume and chip temperature. To compare the various coatings, being given the diversity of the factors to be considered, we worked out an experimental design of complete factorial type offering possibilities of extension so necessary. This methodology of test actually made it possible to follow the evolution of the sizes according to the wear of the tools on ferrous materials treated or not (steel 100C6 treated and untreaded, cast iron FGS600-3). This study made it possible to highlight the interest of the experimental designs for the interpretation of the results and the predictive capacity of this tool compared in particular with the "couple outil-manière" used in french industry. In a systematic way, it appeared that the various coatings had machining and wear behavior specificities (improvement of the coefficients of friction and role of thermal barrier). They condition the formation of the chips (forms, dimensions, states of stresses). Their generally beneficial action makes it possible to consider the development of dry machining. Lastly, this work attempt to model thermaly the chip formation, showing the role of the initial solid chemical bonds rupture in the rise in temperature to the cration of the chip
Iliescu, Daniel. "Approches experimentale et numerique de l'usinage a sec des composites carbone/epoxy". Phd thesis, Paris, ENSAM, 2008. http://pastel.archives-ouvertes.fr/pastel-00005136.
Pełny tekst źródłaGomes, Romeu. "Compréhension des mécanismes de dégradation des outils de découpage à chaud de tôles d'acier trempant au bore-manganèse". Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2018. http://www.theses.fr/2018EMAC0018/document.
Pełny tekst źródłaCar manufacturers are building using a self-hardening high strength boron steel (22MnB5) for safety and environmental concerns. But the shaping of sheets made of these kind of steel imposes on tools severe mechanical stresses and strong thermal transfer. The integration of a blanking function in transfer presses is a response to reach high profitability, but blades are subjected to the same durability problems. The aim of this thesis is to understand how hot blanking tools are wearing in order to give to manufacturers tool material guidelines (X38CrMoV5-3 or X70CrMoV5-2) and process parameters guidelines. To do so, an estimation of mechanical stresses and thermal solicitation is required. The methodology is based on four steps: literature search, hot blanking trials on a specific module of ICA laboratory industrial pilot MEFISTO, finite element simulations of the operation, and microstructural analysis. The state of art is focused on the description of the operation, the physical and mechanical properties of the blank material and tools materials, the blank/tool interface behavior, and the techniques used simulate the hot blanking process. Trials on the hot blanking module provided blanking force and observations of worn blades. These informations are needed to validate the finite element model. This model shows that mechanical stresses are local, intense and slides in the blade cutting edge. Moreover, the blade heating generates a surface temperature close to tool steel tempering temperature. Experimental results compared to numerical ones allow to understand the link between thermo-mechanical stresses and how the damage occurs
Mawissi, Kwamivi. "Modèles de représentation et de définition d'outillages de forme complexe : application à le génération automatique de processus d'usinage". Cachan, Ecole normale supérieure, 1995. http://www.theses.fr/1995DENS0001.
Pełny tekst źródłaJoly, Damien. "Usinabilité de la fonte à graphite vermiculaire". Thesis, Tours, 2010. http://www.theses.fr/2010TOUR4042/document.
Pełny tekst źródłaThis study deals with machinability of compacted graphite iron. This material is in-between grey cast iron and nodular cast iron due to the graphite particle shape. It is used for manufacturing diesel engine blocks so as to increase performances and reduce carbon emissions to comply with Euro 5 norm. It is necessary to compare one material to a reference material to evalute machinability criterium. In our case, compacted graphite iron has been compared to grey cast iron. Tensile tests have given us mechanical properties of our test pieces batch used for machining tests. It helped us to qualify the material in its own material range. Inserts have been characterized by nanoindentation. PVD and CVD coatings were benchmarked in microscratch way to determine their respective adhesion to theirs substrates A design of experiment has been setted up so as to reduce number of inserts protypes to be manufactured. Pin on disk tribologic tests gave few hints to have a better understanding of friction phenomena and wear during compacted graphite iron machining
Koné, Fousseny. "Étude expérimentale, modélisation et simulation numérique de l'usinage à sec des aciers inoxydables : étude de l'effet des revêtements mono et multi-couches". Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0155/document.
Pełny tekst źródłaWhen machining metal alloys, cutting tools are subjected to intense thermomechanical loading, which can lead to a significant reduction of their lifetime. The use of coated tools is then beneficial, in particular during dry machining of stainless steels which are considered as difficult to cut materials. This phD thesis is focused on the effect of coatings addressing aspects of modeling, simulation and experimental tests using tools with complex geometries. Experimental tests under dry turning configuration were performed on an AISI 304L stainless steel with coated and uncoated tools. Particular attention was paid to the temperature evolution, cutting forces and roughness. A wide range of cutting conditions was considered for an advanced understanding of the physical phenomena involved in machining. Experimental results allowed the identification of optimum cutting conditions for the considered tool/workpiece couple and highlighted the importance of coatings in dry machining of stainless steels. In addition, a hybrid analytical/numerical modeling was developed and implemented in DEFORM code. Based on the chip flow direction, 3D forces can be deduced from a 2D numerical simulation of machining. An extraction procedure of real profiles of the tool was introduced using a 3D scanning Breuckmann system. This procedure allows taking into account the real geometry of the tool in numerical simulations. Finally, the comparison between numerical and experimental results allowed the validation of the proposed model
D'Ans, Pierre. "Contribution à la mise au point d'une démarche rationnelle de sélection des traitements de surface: illustration dans le cas des dispositifs de fonderie de l'aluminium". Doctoral thesis, Universite Libre de Bruxelles, 2009. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210366.
Pełny tekst źródła- Utiliser des multitraitements de surface peut se faire en scindant les différentes requêtes en sous-ensembles, de manière à ce que chaque traitement réponde à l’un d’eux. Dans quel ordre ces requêtes doivent-elles être introduites par rapport au substrat ?
- Comment sélectionner les traitements de surface répondant à chaque requête individuelle ?
- Comment classer des multitraitements en termes d’adéquation au problème posé ?
Dans ce travail, les première et troisième questions sont abordées, en explorant les requêtes concernant habituellement les dispositifs de moulage de l’aluminium :
- Résistance aux contraintes d’origine thermique.
- Résistance à la corrosion par les métaux fondus.
- Résistance au frottement.
L’analyse de la bibliographie relative aux traitements de surface utilisés dans ces systèmes a été analysée et des « architectures »-types ont été identifiées (chapitre 3). On prévoit, par exemple, un traitement conférant la résistance à la fatigue superficielle, ainsi qu’un revêtement étanche et résistant à l’aluminium fondu. Une barrière thermique est parfois préconisée.
Pour chacune des architectures, des traitements de surface individuels peuvent être sélectionnés. Un « facteur de performance » permettant de classer les solutions par rapport au problème de la fatigue thermique a été construit (chapitre 4) et discuté dans deux situations :
- Lorsqu’un revêtement est présent, et que les contraintes d’origine thermique (différence de dilatation thermique couche-substrat) menacent de le rompre lors de l’immersion dans un milieu corrosif à haute température. Des essais de corrosion dans de l’aluminium fondu ont été réalisés sur un acier revêtu par du nitrure de chrome dopé à l’aluminium, synthétisé par déposition physique en phase vapeur (chapitre 5 – collaboration :Inasmet).
- Lorsque des variations thermiques rapides menacent de rompre le substrat et la (les) couches. Des essais de fatigue thermique ont été réalisés sur de l’acier à outils pour travail à chaud non traité, boruré ou recouvert d’un multitraitements (zircone yttriée / NiCrAlY / boruration / acier). Le revêtement en zircone yttriée a été obtenu par projection par plasma. L’essai de fatigue thermique a été modélisé et le facteur de performance, discuté (chapitre 6).
Au chapitre 7, les architectures-types ont été introduites dans une méthodologie de sélection des multi-traitements de surface, qui a été appliquée dans deux cas :
- Celui des moules de fonderie, devant résister à la fatigue thermique et à la corrosion par l’aluminium fondu. Le facteur de performance a été extrapolé à d’autres situations qu’aux chapitres 5 et 6. Les solutions habituellement proposées pour résoudre ce problème sont retrouvées.
- Celui de deux pièces en acier frottant l’une contre l’autre en présence d’aluminium fondu.
To select surface treatments, one must account for the required functional properties, the substrate features and the solicitations the substrate must endure. Certain combinations of these parameters make it difficult to select a single surface treatment, a reason why several successive treatments are preferred. To select them, one needs to determine:
- How to divide the several requests into groups and how to stack up these groups from the substrate to the outer surface, so that each treatment deals with one specific group of requests/properties.
- How to select individual layers for each group of properties.
- How to rank the multi-treatments in terms of relevance for a given application.
In this work, one tries to answer the first and the third questions, by studying the case of aluminium foundry, in which the industrial devices frequently face the following solicitations:
- Thermal stress (thermal fatigue, thermal expansion mismatch).
- Presence of corrosive molten metal.
- Sliding wear.
In the literature, several “standard” architectures are proposed (chapter 3), like a diffusion layer reducing superficial fatigue plus a corrosion barrier layer. A thermal barrier coating is also sometimes proposed.
For each of these architectures, one can select individual treatments. To rank them, one devised a “performance index” for thermal stress (chap.4), which is discussed for two cases:
- For large differences between layer and substrate thermal expansion coefficients, when both are put into contact with a high temperature corrosive medium, the layer may be damaged. One discusses this case by examining the corrosion caused by molten aluminium for a steel substrate coated by anticorrosive chromium nitride doped with aluminium. The layer is produced by physical vapour deposition (chap. 5 – cooperation: Inasmet).
- Repeated fast surface temperature transients can also damage the substrate and/or the layer by thermal fatigue. One conducted thermal fatigue tests with samples of hot work tool steel, respectively untreated, simply borided and protected by a multilayer. In the last case, top coat is yttria stabilised zirconia, followed by a nickel superalloy and then a borided layer (undercoat). One synthesized the zirconia coating by plasma spray and one modelled the thermal fatigue (chap. 6).
In chap. 7, architectures from chap. 2 are introduced in a multi-treatment selection routine, which is applied in two cases:
- Foundry moulds for molten aluminium, withstanding both thermal fatigue and corrosion. The devised performance index is extrapolated beyond the tests of chap. 5 and 6 to treatments for this industrial application, thereby quantifying their respective merits.
- A foundry device exposed to molten metal and sliding wear.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished