Tesis sobre el tema "Mechanical et Tribological properties"
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Gui, Yunfang. "Mise au point par pulvérisation cathodique magnétron en condition réactive et caractérisations mécaniques et tribologiques de revêtements de phases Magnéli de titane (TinO2n-1)". Thesis, Belfort-Montbéliard, 2014. http://www.theses.fr/2014BELF0235/document.
Texto completoThe present work deals with the synthesis and the structural, mechanical and tribological characterization of titanium Magnéli phases (TinO2n-1) coatings for tribological application. The thin films were prepared by reactive magnetron sputtering from titanium target in a reactive O2/Ar gas mixture using a rotating and heating substrate holder.The first part of the study is based on the synthesis of titanium Magneli phase monolayers. The influence of the main synthesis parameters (oxygen flow rate, temperature of the substrate holder) was analyzed in relation with the structure and the morphology of the synthesized coatings. Then TinO2n-1/AlTiN bilayers were synthesized by the reactive magnetron sputtering and the low pressure electric arc techniques, respectively. The phase and the thickness of the top layer of titanium oxide and the thickness of the under layer AlTiN were selected as the parameters to be studied.The second part concerns the mechanical properties (nano hardness instrumented, elasticity modulus, Mercedes test and scratch test) and tribological properties (pin on disc test) of the monolayer and bilayer coatings. Particular attention was paid to the influence of the friction test temperature on the bilayer coatings wear rates
Tonicello, Emmanuel. "Etude et modélisation de la fatigue de contact en présence d’indentation dans le cas de roulements tout acier et hybrides". Thesis, Lyon, INSA, 2012. http://www.theses.fr/2012ISAL0047/document.
Texto completoThe nitrided 32CrMoV13 steel is a gradient properties material used for the production of aeronautical bearing rings. The principal advantages are its surface hardness and core ductility, useful against debris denting. Moreover, to improve rolling bearing performances, ceramic balls (silicon nitride Si3N4) instead of steel (M50). The present study aims to investigate the contact fatigue performance in presence of indentation for two pairs of materials (nitrided 32CrMoV13 steel / M50 and nitrided 32CrMoV13 steel / Si3N4). This performance is mainly oriented in terms of lifetime of the indented contact by a crack initiation criterion. A study of the mechanicals properties of the nitrided 32CrMoV13 steel, required for the application of the criterion, is then performed. It allows to characterize the hardening law and the cyclic micro-plastic behavior of the nitrided layer of the nitrided 32CrMoV13 steel. Crack initiation properties of the nitrided surface layer have been evaluated by compression tests on thin hollow cylindrical specimens with small cylindrical holes. The contact fatigue behavior in presence of indentations was studied on a high-speed twin-disks machine. These tests allowed to characterize the difference in behavior of nitrided 32CrMoV13 steel (indented) in a steel-to-steel contact or steel-to-ceramic contact. The major effect of sliding has been highlighted. All these experimental studies were coupled with numerical simulations to calibrate the physical model of crack initiation and to show its capabilities. In conclusion a new model of rolling contact fatigue life has been proposed. It is specifically adapted to operation in presence of residual stresses such as resulting from debris denting. The model uses mechanical properties that have been identified for thermo-chemically treated layers of nitrided 32CrMoV13 steel
Papy, Kévin. "Compréhension et maîtrise de la mise en oeuvre des cermets par procédé de fusion laser sur lit de poudre pour la réalisation de pièces anti-usure". Electronic Thesis or Diss., Ecully, Ecole centrale de Lyon, 2023. http://www.theses.fr/2023ECDL0025.
Texto completoTechnogenia® is a French company, founded in 1979, specialized in hardfacing solutions based on tungsten carbide welding overlays. As part of the thesis, Technogenia® wishes to assess the suitability of using Additive Manufacturing technology to produce wear-resistant parts based on tungsten carbide. The company's primary objective is to use laser-powder bed fusion (L-PBF) technology to produce tungsten carbide-based parts that approach the mechanical characteristics of tungsten carbide-based parts made by conventional processes. The aim of this thesis is to study the feasibility of producing tungsten carbide-based parts, and to characterize the microstructures and mechanical and wear properties of parts produced by Additive Manufacturing. The properties of materials obtained using the L-PBF process will be compared with the known properties of parts produced by conventional processes. Firstly, two tungsten carbide-based powders with metal binders (cemented carbides) are selected for parametric optimization in the L-PBF process. This step is carried out by analyzing the influence of the main process parameters (laser power, scanning speed, scanning strategy, vector deviation, layer thickness, etc.) on the materials. An experimental design is defined in several steps, such as the production of beads, surfaces and cubes, in order to determine the main parameters. Two types of thermal post-treatment are carried out to study the influence on the materials and to eliminate certain structural defects. Microstructural differences between the two binders are analyzed and studied. Numerous phenomena due to the laser process are observed and commented on during sample analysis. Secondly, the samples successfully manufactured are subjected to mechanical and tribological characterization. Various mechanical tests (hardness, toughness, impact strength) are carried out to characterize and compare L-PBF materials with a reference material produced by conventional methods
Ahmed, Omer. "Tribological and Mechanical properties of Multilayered Coatings". University of Toledo / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1501763970144729.
Texto completoSow, Mourtada Aly. "Alliages à Haute Entropie (AHE) pour revêtements hautes performances". Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR026.
Texto completoThis thesis aims to develop high performance coatings from high entropy alloys powders (HEA) and to characterize them. This work is divided in two parts. The first part consists in the synthesis of HEA powders for a family of alloy elements Al, Cr, Fe, Mn and Mo by mechanical alloying.These powders were characterized by XRD, SEM and Mössbauer spectrometry. These powders have a CC1 and CC2 type crystal structure. The heat treatment of the powders (500, 650, 800 and 950 °C) allowed to obtain a structural stability at 650 °C/ 1h, at 800 °C/ 1h and 950°C/ 1h and 4h, a structural evolution of the powders was noticed. The CC1 phase disappears in favor of the CC2 phase and the M23C6 et M6C type carbides. At the result of these characterizations, the chemical composition 19Al-22Cr-34Fe-19Mn-6Mo powder was preserved and produced in suffering quantities by mechanical synthesis (powder A) and by mixing (powder B).In the second part of this work, thick and thin HEA coatings were developed by laser fusion and magnetron sputtering respectively from A and B powders. The thick laser-melted coatings were deposited on steel substrate. The structure and microstructure of the deposits were carefully characterized by XRD, SEM, EDS, EBSD and TEM. The results of these characterizations revealed that the thick deposits are chemically heterogeneous. Moreover, these coatings showed different structures and microstructures of solidification depending on the deposition conditions and the powders (A or B) pre-deposited to realize these coatings.The HEA thin film were deposited on silicon wafer and steel substrate. The deposition conditions of the thin films were optimized and the chemical composition was controlled. The heat treatments of the thin films revealed good structural and microstructural stability up to 800 °C/ 72h. Corrosion resistance, mechanical properties and tribological performances were evaluated
Hoskins, Thomas James. "The mechanical and tribological properties of PEEK gears". Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/6047/.
Texto completoBull, Stephen John. "The mechanical and tribological properties of ion implanted ceramics". Thesis, University of Cambridge, 1988. https://www.repository.cam.ac.uk/handle/1810/244798.
Texto completoIzadi, Sina. "Al/Ti Nanostructured Multilayers: from Mechanical, Tribological, to Corrosion Properties". Scholar Commons, 2016. https://scholarcommons.usf.edu/etd/6265.
Texto completoLuo, Huan. "Study of the plasma phenomenon in HiPIMS discharge. : Application to the reactive deposition of tantalum and hafnium carbide nanocomposite coatings and characterization of their physicochemical, structural, mechanical and oxidation resistance propertie". Thesis, Bourgogne Franche-Comté, 2020. http://www.theses.fr/2020UBFCA010.
Texto completoHigh Power Impulse Magnetron Sputtering technology (HiPIMS) has been developed and considered as an effective method for film preparation. HiPIMS technology allows for much greater flexibility for manipulating film structure and performance, leading to films with unique properties that are often unachievable in the other PVD approaches. However, the underlying plasma mechanism for supporting film growth is currently blurred. Moreover, HiPIMS technology is still stationed in the laboratory, many films with desirable properties have not been explored under HiPIMS framework. In this work, (i) the driven mechanism of high density plasma coherent structure (i.e., spokes) in the HiPIMS discharge and (ii) how the structure and properties of the TaC/a-C:H and HfC/a-C:H films are regulated by HiPIMS were investigated. For the driven mechanism of spokes, based on the dispersion relationship of HiPIMS plasma and the evolution of the coupling between two azimuthal waves, the coupling-induced wave model was proposed. For the TaC/a-C:H and HfC/a-C:H films, the chemical bond states, structure, morphology, mechanical and tribological properties, thermal stability as well as oxidation resistance of the films were investigated. By comparison with DC deposited films, it is demonstrated that HiPIMS technology provides a potential strategy for preparing higher performance TaC/a-C:H and HfC/a-C:H films in terms of hardness, friction coefficient and wear resistance, oxidation resistance and thermal stability by modulating the chemical bonding state and nanocomposite structure of the films through HiPIMS reactive plasma
Wang, Shuo y 王硕. "Tribological behaviour of anodised alumina nanohoneycombs". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B49618131.
Texto completopublished_or_final_version
Mechanical Engineering
Master
Master of Philosophy
Burgess, Ian C. "Tribological and mechanical properties of compliant bearings for total joint replacements". Thesis, Durham University, 1997. http://etheses.dur.ac.uk/4720/.
Texto completoEfeoglu, Ihsan. "The mechanical and tribological properties of ceramic sputter ion-plated coatings". Thesis, University of Salford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334034.
Texto completoXu, Songbo. "Mechanical and Tribological Properties of Carbon Nanofiber Reinforced High Density Polyethylene". Diss., North Dakota State University, 2014. https://hdl.handle.net/10365/27288.
Texto completoHagg, Lobland Haley E. "Definition of Brittleness: Connections Between Mechanical and Tribological Properties of Polymers". Thesis, University of North Texas, 2008. https://digital.library.unt.edu/ark:/67531/metadc9097/.
Texto completoHagg, Lobland Haley E. Brostow Witold. "Definition of brittleness connections between mechanical and tribological properties of polymers /". [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-9097.
Texto completoSwisher, Mathew M. "A molecular dynamics study of the tribological properties of diamond like carbon". Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/129046.
Texto completoCataloged from student-submitted PDF of thesis.
Includes bibliographical references (pages 103-111).
Diamond like carbon (DLC) is an attractive choice as a coating for mechanical components, because of its excellent wear resistance and very low coefficient of friction . We use molecular dynamics (MD) simulations with a reactive force field (ReaxFF) to study the friction and wear between DLC counterfaces, both in comparison to and in contact with steel counterfaces. We show that the tribological properties of DLC in dry sliding friction are heavily dependent on both the structure of the DLC as well as the passivation layer that forms on the sliding counterfaces under different environmental conditions, and that when optimizing for the lowest COF the best structure for the DLC depends on the type of passivation layer. We also find that, by preventing bonding across the counterfaces as the thin film of lubricant is squeezed out at the point of contact, the passivation layer is instrumental in the material's ability to resist scuffing and wear. Additionally, we find that the strength and hardness of DLC makes damaging the passivation layer due to contact forces unlikely under real world conditions. Finally, we use MD simulations to study in more detail the transition from lubricated to dry friction, and in particular, the role of DLC surface chemistry and the resulting passivation layer in this transition. Our work shows that the frictional force can be described quite accurately across the transition from pure slip ( dry friction) to the purely hydrodynamic regime using a simple model which superposes the two effects, provided it also accounts for any immobile fluid layers at the fluid-solid interface. We show that, for water lubrication, the transition from the pure slip to the purely hydrodynamic regime occurs at smaller lengthscales in DLC counterfaces compared with steel.
by Matthew M. Swisher.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Mechanical Engineering
Akkaya, S. S., V. V. Vasyliev, K. Kazmanl, A. A. Luchaninov, E. N. Reshetnyak, N. Solak, V. E. Strel’nitskij y M. Ürgen. "Mechanical and Tribological Properties of TiN Coatings Produced by PIII&D Technique". Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35187.
Texto completoWeick, Brian L. "Effects of fiber type on the tribological behavior of polyamide composites". Diss., This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-10192006-115602/.
Texto completoRoy, Amit. "Tribological Performance of Polymer Based Self-lubricating Coatings". Thesis, Luleå tekniska universitet, Maskinelement, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-75576.
Texto completoStone, D’Arcy S. "Silver Tantalate: a High Temperature Tribological Investigation". Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc700025/.
Texto completoCOSTA, MARCELO EDUARDO HUGUENIN MAIA DA. "STRUCTURAL, MECHANICAL, TRIBOLOGICAL PROPERTIES AND THERMAL STABILITY OF FLUORINATED AMORPHOUS CARBON FILMS DEPOSITED BY PECVD". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2005. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=6376@1.
Texto completoNeste trabalho são apresentados os efeitos nas propriedades mecânicas, estruturais e tribológicas da incorporação de flúor em filmes de carbono amorfo hidrogenados depositados por Deposição na Fase Vapor Assistido por Plasma . A estabilidade térmica de filmes de carbono amorfo fluorados também foi estudada. Os filmes foram depositados a partir de uma mistura dos gases C2H2 e CF4 com uma tensão de autopolarização de - 350V. A mistura de gases da deposição foi variada de uma concentração de 0% até 90% de CF4. A estabilidade térmica foi verificada em filmes depositados com 50% de C2H2 e 50% de CF4 na atmosfera precursora. Os filmes foram submetidos a temperaturas variando de 200oC a 600oC por 30 minutos. As propriedades mecânicas, estruturais e tribológicas dos filmes foram estudados com o uso de técnicas nucleares (retroespalhamento de Rutherford e Detecção por recuo elástico), espectroscopia Raman, espectroscopia de fotoelétrons induzida por raios-X, perfilometria (tensão interna), nanoindentação (dureza), de microscopia de força atômica e de ângulo de contato. Os resultados obtidos mostraram que a incorporação de flúor produzem filmes com as propriedades indo em direção às propriedades do Teflon. Os filmes ricos em flúor são menos densos, mais macios, mais hidrofóbicos e tem um menor coeficiente de atrito do que filmes de carbono amorfo hidrogenados. O tratamento térmico realizado mostrou que os filmes são estáveis a temperaturas de até 300oC. A partir desta temperatura os filmes sofreram perda de flúor e mudanças nas suas propriedades indicando a formação de uma estrutura mais grafítica.
This work presents the effects on the mechanical, structural and tribological properties of the incorporation of fluorine in amorphous carbon films deposited by PECVD (Plasma Enhanced Chemical Vapor Deposition). The thermal stability of fluorinated amorphous carbon films was also studied. The films were deposited using mixtures of C2H2 and CF4 gases with a self-bias voltage of - 350V. The concentration of CF4 in the gases mixture was varied from 0% to 90%. The thermal stability was investigated in films deposited with 50% C2H2 and 50% CF4 as precursor atmosphere. These films were annealed in the temperatures range of 200oC to 600oC during 30 minutes for each sample. The mechanical, structural and tribological properties were studied using nuclear techniques (Rutherford Backscattering and Elastic Recoil Detection Analysis), Raman and X-ray photoelectron spectroscopy, profilometry (for internal stress) and nanoidentation (for hardness), atomic force microscopy and contact angle measurements. The results showed that fluorine incorporation produces films with properties resembling the Teflon's properties. The films rich in fluorine appear to have lower density, more hydrophobicity and lower friction coeficient than amorphous carbon films. They are also softer than them. The thermal annealing shows that films were thermally stable within temperatures up to 300oC. Above this temperature the films tend to loose fluorine and their properties change revealing a more graphitic structure.
Ghasemi, Rohollah. "The influence of microstructure on mechanical and tribological properties of lamellar and compacted irons in engine applications". Doctoral thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Material och tillverkning, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-32052.
Texto completoShah, Rakesh K. "Enhancements of Mechanical, Thermal Stability, and Tribological Properties by Addition of Functionalized Reduced Graphene Oxide in Epoxy". Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc699889/.
Texto completoTASAYCO, CARLOS MANUEL SANCHEZ. "STRUCTURAL, MECHANICAL AND TRIBOLOGICAL PROPERTIES OF TIB2 AND TI-B-N FILMS DEPOSITED BY REACTIVE DC MAGNETRON SPUTTERING". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=10020@1.
Texto completoCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
O presente trabalho teve como objetivo central o estudo das modificações nas propriedades estruturais, mecânicas e tribológicas causadas pela incorporação de nitrogênio em filmes de diborato de titânio (TiB2) crescidos pela técnica de erosão catódica assistida por um campo magnético. Os revestimentos de Ti-B-N com diferentes conteúdos de nitrogênio foram depositados em substratos de silício cristalino (100) a partir da erosão de um alvo de diborato de titânio mediante o uso da técnica de erosão catódica em uma atmosfera de argônio e nitrogênio e com tensões de polarização variando entre +100V e - 100V. Os efeitos do conteúdo de nitrogênio e a influência da tensão de polarização na estrutura e no comportamento tribológico foram investigados com o uso da técnica nuclear de retroespalhamento Rutherford (RBS), espectroscopia de fotoelétrons induzida por raios-x (XPS), difração por raios-x (XRD), perfilometria (medidas de tensão interna), microscopia de força atômica (AFM) e de ângulo de contato. Os resultados do presente trabalho mostraram que a incorporação de nitrogênio produz filmes com tensões internas cada vez mais compressivas. No entanto a mudança da tensão de autopolarização a valores positivos provocou uma relaxação na tensão interna. Nesses casos, foi observada uma melhor adesão dos filmes aos substratos de silício. Os resultados de XPS mostraram que as fases, TiB2, BN e TiN, estão presentes nos filmes de Ti-B-N e a caracterização por XRD determinou a estrutura nanocristalina desses revestimentos. Medidas de AFM indicaram valores de rugosidade superficial entre 1 e 2nm.
The main purpose of the present work was the study of the effects on the structural, mechanical and tribological properties of the incorporation of nitrogen in titanium diboride films (TiB2) grown by reactive dc magnetron sputtering. Ti-BN coatings with different N contents were deposited on Si (100) substrates from a TiB2 target. The sputtering was carried out in an Ar-N2 gas mixture with a substrate bias voltage in the range between +100V e -100V. The effects of the nitrogen content and the influence of substrate bias voltage on the coatings properties were studied by Rutherford Backscattering Spectrometry (RBS), XRay photoelectron spectroscopy (XPS), X-Ray diffraction (XRD), profilometry (internal stress measurements), atomic force microscopy (AFM) and contact angle measurements. The results of the present work show that nitrogen incorporation produces films with higher compressive internal stress. However, a positive substrate bias reduces the compressive stress, thus resulting in a better adhesion to the substrate. The XPS results showed that the TiB2, TiN and BN phases are present in the Ti-B-N films. Characterization by XRD determined the nanocrystalline structure of Ti-B-N coatings. Measurements by AFM revealed low surface roughness values.
Sanni, Onimisi Calistus. "Microstructural, Mechanical and Tribological Studies of Ti-6Al-4V Thin Plates Produced by EBM Process". Thesis, Högskolan Dalarna, Materialteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:du-35321.
Texto completoFallqvist, M., R. M’Sauobi, J. Andersson y Mikael Olsson. "Mechanical and tribological properties of PVD-coated cemented carbide as evaluated by a new multi-pass scratch testing method". Högskolan Dalarna, Materialteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:du-11438.
Texto completoOpen Access
Liu, Chang. "Structure, mechanical and tribological properties of hydrogen-free amorphous carbon films deposited by dual-frequency mode pulsed-DC magnetron sputtering". Thesis, University of Sheffield, 2017. http://etheses.whiterose.ac.uk/17921/.
Texto completoSingh, Harpal. "An Investigation of Material Properties and Tribological Performance of Magnetron Sputtered Thin Film Coatings". University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1449850005.
Texto completoCross, Tsali Jacob. "Mechanical properties of polymer-derived ceramics constituted from silicon-carbon-oxygen-nitrogen and their tribological behavior in dry and humid environments". Diss., Connect to online resource, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3207728.
Texto completoSaggar, Richa. "Processing and Properties of 1D and 2D Boron Nitride Nanomaterials Reinforced Glass Composites". Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-263205.
Texto completoDeva, Reddy Jayadeep. "Mechanical properties of Silicon Carbide (SiC) thin films". [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002615.
Texto completoHankla, Lorenzo W. "Mechanical properties of particulate-reinforced boron carbide composites". [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002749.
Texto completoKarniychuk, Maksim. "Combination of Lateral and Normal Forces for Investigation of Mechanical Properties and Tribological Behaviour of Bulk and Coated Materials on the Micro-Scale". Doctoral thesis, Universitätsbibliothek Chemnitz, 2006. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200601120.
Texto completoIn der zweiten Hälfte des 20. Jahrhunderts und während den ersten Jahren des 21. Jahrhunderts wurden zahlreiche Methoden zur Untersuchung mechanischer und tribologischer Materialeigenschaften auf der Mikro- und Nanometerskala entwickelt. Trotz der Fortschritte auf diesem Gebiet blieben vielfältige Fragestellungen unbeantwortet oder waren mit den vorhandenen experimentellen Untersuchungsmethoden nicht zugänglich. Mit der kombinierten Belastung aus Lateral- und Normalkräften wurden die etablierten Messverfahren um einen viel versprechenden Ansatz zur Charakterisierung mechanischer sowie tribologischer Eigenschaften erweitert, der sowohl für Massiv- als auch Schichtmaterialien anwendbar ist. Die einzigartige Konstruktion einer Lateralkrafteinheit bietet als separates Bauteil die Möglichkeit während eines Standardeindringversuches mittels des kommerziellen Nanoindenters UMIS 2000 bei normaler Last, eine laterale Belastung zu überlagern. Die vorliegende Arbeit zeigt eine detaillierte Studie der Einsatzmöglichkeiten der Lateralkrafteinheit hinsichtlich der Charakterisierung mechanischer Eigenschaften und tribologischen Materialverhaltens auf der Mikrometerskala. Zunächst wurde herausgefunden, dass eine Verkippung der Lateralkrafteinheit von 3,3° gegenüber dem UMIS-Rahmen notwendig ist, um eine hochgenaue und definierte Belastung aus lateraler und normaler Kraft auf die Probe auszuüben. Mit dieser durchgeführten Korrektur der Ausrichtung gelang es weitere auf den Messprozess einwirkende Effekte zu minimieren. Nach der Korrektur der thermischen Drift scheinen die gemessenen Normalverschiebungs-Zeit-Kurven für die Bestimmung von mechanischen Parametern wie maximaler Verschiebung oder bleibender Eindrucktiefe bei lateraler Belastung geeignet zu sein. Als ein weiteres Ergebnis gelang es, durch die kombinierte Belastung der Kraftkomponenten Bruchversagen nachzuweisen. Das Materialversagen wurde durch eine abrupte Änderung der lateralen Verschiebung im Last-Verschiebungs-Diagramm angezeigt. Mit dieser Methode wurde erstmalig in-situ das Bruchversagen am Beispiel des einkristallinen Saphirs detektiert. Die kritische Zugspannung, die zur Bruchbildung bei Saphir führte, war 9,68+-0,22 GPa. Die Analyse der Kurvenform der Kraft-Verschiebungs-Kurven für die Lateralbelastung im Zusammenhang mit dem Auftreten von bleibender Deformation in den zugehörigen Verschiebungs-Zeit-Kurven der normalen Belastung liefert den Beginn der plastischen Deformation. Massive BK7-Glasproben sowie SiO2-Schichten wurden untersucht. Für die Fließspannung der SiO2-Schicht wurde ein Wert von 6,83+-0,02 GPa ermittelt. Der Haftreibungskoeffizient für verschiedene Materialpaarungen wurde aus den Last-Verschiebungs-Kurven mit einer Genauigkeit von 5-10 % berechnet. Zu den untersuchten Materialien gehörten Quarz, einkristallines Saphir, BK7-Glas sowie SiO2-, DLC- und CrN0.08-Schichten, die mit Diamant, Wolframkarbid und Saphir-Indentern gepaart wurden. Zusätzlich wurde der Einfluss der Normallast auf den Haftreibungskoeffizienten für Quarz und BK7-Glas gegen Diamant studiert. Es zeigte sich, dass der Beginn der plastischen Deformation zu signifikanten Änderungen der Haftreibung führt
Paul, Arindam. "Development and evaluation of NiW alloy and NiW-TiO2 composite coatings on the mechanical properties, tribological performance and the corrosion resistance of bearing steel". University of Akron / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=akron1618853855083468.
Texto completoPrashanth, Konda Gokuldoss. "Selective laser melting of Al-12Si". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-144245.
Texto completoHaviez, Laura. "Etude expérimentale et modélisation d'un contact graissé soumis à des sollicitations de fretting-reciprocating". Thesis, Ecully, Ecole centrale de Lyon, 2015. http://www.theses.fr/2015ECDL0051.
Texto completoElectrification of flight controls represents an important milestone for both civil and military next-generation aircraft. A successful development of electro-mechanical actuators used for this type of application not only requires the establishment of a set of appropriate objectives and criteria but also the study of fundamental aspects. These studies mainly focus on the mechanical and tribological behavior of parts in contact with the objective to prevent seizing. Seizing is defined as an irreversible blockage of the system and it can be considered as the worst-case scenario. As a matter of fact, the considered electro-mechanical actuators are subjected to vibrational loads which induce small displacements between the parts in contact. These micro-slidings can result in wear, cracking, scaling and other undesirable phenomena. This PhD thesis is divided into four major topics that each contributes to prevent seizing. More precisely, the first part of this thesis deals with the tribological behavior of the first bodies in dry condition both with and without surface treatments. As a second axis the different lubrication regimes of the greased lubricated interface were determined. We have shown that the total lubrication regime is characterized by the formation of a lubricant and protective tribofilm. A detailed analysis on the nature of the tribofilm as well as on its kinetics of formation and destruction was carried out. The third area is devoted to the study of the tribological behavior of the coated and greased contact. Finally, the fourth axis of this research deals with the question of how we can simulate and predict wear, and seizing as its most severe form, under multiple loading conditions. These four complementary areas allowed us to establish tools for comparison for greases and coatings in order to understand the behavior of the fretted interface and to develop simulation tools
El, Sayed Sayeda M. A. "Effect of gamma irradiation on the mechanical properties of semicrystalline polyethylene terphthalate(PET)". Doctoral thesis, Universite Libre de Bruxelles, 1988. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/213325.
Texto completoHe, Wei. "Mechanical and microstructural properties of thin metal films on compliant substrates". Thesis, Poitiers, 2016. http://www.theses.fr/2016POIT2280/document.
Texto completoThe mechanical behavior of metallic thin films deposited on soft substrates plays a crucial role in the performance of flexible electronics and MicroElectroMechanical Systems (MEMS).At first, a novel method is presented to characterize the in-plane elastic modulus of sub micrometer thin films. With two coating layers bonded symmetrically to half polyimide substrates, Digital Image Correlation (DIC) has been employed to measure time-resolved full-field strain maps of film and substrate during in situ tensile testing. The strain differences between virgin and composite parts allowed to extract the elastic properties of the thin films in a simple way with high precision. As expected, the strain distribution is uniform through the film thickness which indicates a perfect adhesion between the film and the substrate. In the case of tungsten, chromium, nickel and copper films, the values obtained are close to the bulk one.In a second step, a new experimental method using uniaxial tensile testing is presented to study Bauschinger effect in thin metallic films deposited on stretchable substrates. Thanks to our new pre-tensile setup (specific grips), the thin films were deposited on pre-stretched substrates and thus could be deformed alternately in tension and compression within a large strain domain. The elastic intra-granular strain of polycrystalline thin films and true strain of substrates are measured in situ by X-Ray Diffraction (XRD) and DIC. From lattice strain-true strain curves, the mechanical response of copper and nickel /substrate sets is analyzed in view of the complete loading history and the presence of residual stresses and crystallographic texture in thin films
Imbert, Laurianne. "Effets de l'ostéogénèse imparfaite sur les propriétés mécaniques et minérales de l'os cortical chez l'enfant". Thesis, Ecully, Ecole centrale de Lyon, 2014. http://www.theses.fr/2014ECDL0042/document.
Texto completoOsteogenesis Imperfecta (OI) is a genetic disorder, also known as the “brittle bone disease”, associated with an increased bone fragility. Several phenotypes exist, reflecting different severities but some features are frequently observed like a reduced stature and long bone deformities. A few treatments are currently used but none of them is curative. To improve those treatments there is a need for a better understanding of the mechanisms involved. Therefore, the objective of this work is to investigate the effects of OI on the bone tissue at macroscopic and tissue scales. The main interest of this project is to perform a comparative study between a group of OI bones retrieved from children with OI and a group of control bones retrieved from healthy children. The mechanical, mineral and structural properties of those two groups were compared using high resolution computed tomography, nanoindentation, spectroscopy Raman, scanning electron microscopy, digital image correlation and compression testing. The osteoclast activity on those two types of substrates was compared by interferometry. Finally, the virtual fields method was applied to identify elastic moduli of interstitial and osteonal zones in bone tissue. The tissue quality, the remodeling activity and the microstructure were altered in OI, those modifications can explain the increased fragility of OI bones
Huyghe, Pierre. "ON THE RELATIONSHIP BETWEEN MICROSTRUCTURE DEVELOPMENT AND MECHANICAL PROPERTIES IN Q&P STEELS". Doctoral thesis, Universite Libre de Bruxelles, 2018. https://dipot.ulb.ac.be/dspace/bitstream/2013/278740/5/contratPH.pdf.
Texto completoDoctorat en Sciences de l'ingénieur et technologie
info:eu-repo/semantics/nonPublished
Ben, jaber Nader. "Élaboration de revêtements prothétiques : Caractérisation physico-chimique, structurale et mécanique". Thesis, Reims, 2016. http://www.theses.fr/2016REIMS010/document.
Texto completoThis work presents an innovative process to develop prosthetic calcium phosphate coatings: electrodeposition. It focuses on the synthesis and characterization of calcium phosphates for the recovery of hip prostheses. Thus, an original protocol was developed, which combines pulsed current electrodeposition to a heat treatment method under controlled atmosphere called THUCA. Morphology, composition and structure of the coatings obtained were analyzed respectively by SEM, X-ray microanalysis and X-ray diffraction. The results showed that we obtain an implant consisting of a two-phases coating (HAP hydroxyapatite and tricalcium phosphate b-TCP) on the titanium alloy TA6V.Mechanical characterizations made by indentation, scratch tests (scratch test) and wear (tribological) for the first time on this implant showed that the coating has a good adhesive and cohesive appearance with improved wear resistance. Moreover, the bioactivity of the developed coatings was evaluated by studying their corrosion behavior in physiological medium and also their behavior in cell culture medium. All these results indicate that the proposed implant has good properties making it a good candidate as an implant for orthopedic surgery.Furthermore, this thesis was completed by preliminary studies of a complementary technique to electrodeposition: electrophoresis. We obtain for the first time a coating consisting of nano-particles of hydroxyapatite having good mechanical properties
Andrešiūnas, Aurimas. "Bioskalių tepamųjų medžiagų dilimo slopinimo savybių tyrimas". Master's thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110602_120441-47126.
Texto completoAt this work there are accomplished researches of biological properties of lubricating materials bio-tribological features and disputed obtained results. This work discusses bio-tribological properties of lubricating materials results. Tests were used rapeseed oil additives modified next: stearic acid, oleic acid, monoglycerides, monodiglycerides and their compositions. Investigation shows, that the modification of rapeseed oil substances and mixtures there of effectively inhibits wear and effectively reduces friction, even for commercial bio oil. The investigation revealed that the modified rapeseed oil oleic acid improves friction surfaces to wear protection. It was found that a mixture of rapeseed oil with 2% oleic acid and 0.5% monodiglycerides accessories not only ensure the minimum of friction losses in the moment, but these losses during the test have a tendency to decrease.
Patil, Amit k. "ADVANCED PROCESSING OF NICKEL-TITANIUM-GRAPHITE BASED METAL MATRIX COMPOSITES". Cleveland State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=csu1560298763233401.
Texto completoTossou, Eric. "Développement de nouveaux composites hybrides renforcés par des fibres de carbone et de lin : mise en oeuvre et caractérisation mécanique". Thesis, Normandie, 2019. http://www.theses.fr/2019NORMC209/document.
Texto completoThe goal of this thesis is, on the one hand, the optimization of the manufacturing of composite materials through the study of the behavior of dry fibrous reinforcements in compaction and, on the other hand, the development and characterization of hybrid composite laminates reinforced with carbon and flax fibers. During the manufacturing process of these composites, the reinforcements are subjected to a phenomenon called transverse compaction. Understanding this mechanism is important for improving the manufacturing process. Knowledge of the compaction capacity of the dry reinforcements also serves to predict the fiber content as well as the thickness of the final composite part. Compaction tests carried out on twelve reinforcements presenting different technical solutions have shown that the compaction capacity of a dry reinforcement is influenced by several factors. The results obtained from this work, which focuses on natural fiber reinforcements (flax), have shown that these types of reinforcement are less compactable than synthetic fiber reinforcements (carbon, glass). Thus, to be able to improve the compaction capacity of these natural reinforcements, it is necessary to choose those whose area density is important, those whose tows are in fiber not in yarn, those which are unidirectional (or quasi UD) rather than woven or bi-bias. In addition, it is necessary to choose a multi-ply sequence rather than single-ply sequence. Faced with a strong need for lightening structures, composite materials are increasingly sought in the industrial sector, particularly in the transport sector. However, composite materials like any other material, in addition to being mechanically efficient, must perform other functions such as damping shock and vibration for good performance in service. To meet this double requirement, one of the solutions is to use the hybridization technique which consists in using within the same composite natural and synthetic fibers at the same time in order to exploit their respective advantages. Respectively because of their rigidity and their damping capacity, the carbon and flax fibers were chosen in the context of this thesis. The characterization of the laminate composite plates manufactured with resin infusion process shows that the carbon composite has better mechanical and microstructural properties while the flax composite offers very interesting damping properties. The results show that hybridization of flax with carbon considerably improves the low mechanical properties of the flax composite and the poor damping properties of the carbon composite. The stacking sequence of layers has a significant influence on the behavior and properties of the hybrid laminates. Our results showed that to have a better microstructure the carbon layers must be put outside. This way of hybridizing also makes it possible to obtain better properties in flexion and shock. By contrast, when the flax layers are placed outside, the hybrid composite has a better damping capacity. This stacking sequence also guarantees a better indentation strength. Thus, the hybrid stacking sequence to choose will depend on the need that is sought to meet. Finally, thanks to an analysis based on classical laminate theory, it has been demonstrated in this thesis that hybrid composite laminates can be dimensioned despite the fact that the constituent layers are of different types with dissimilar properties
Ghosh, Abhijeet. "Study of Mechanical and Tribological Properties of AZ91/SiC Composites". Thesis, 2018. http://ethesis.nitrkl.ac.in/9651/1/2018_MT_216ME6418_AGhosh_Study.pdf.
Texto completoRajkonwar, Amit. "Investigation into mechanical and tribological properties of Lantana Camara particulate reinforced epoxy composite". Thesis, 2017. http://ethesis.nitrkl.ac.in/9688/1/2017_MT_215ME6235_ARajkonwar_Investigation.pdf.
Texto completoRekha, Rattan. "Investigations on mechanical and tribological properties of carbon fabric reinforced polyetherimide composites". Thesis, 2006. http://localhost:8080/xmlui/handle/12345678/4512.
Texto completoBasumatary, Kamal Kumar. "Investigation into Mechanical and Tribological Properties of Ipomoea carnea Reinforced Epoxy Composite". Thesis, 2013. http://ethesis.nitrkl.ac.in/5168/1/211ME1375.pdf.
Texto completoSwain, Biswajit Kumar. "Mechanical, Tribological and Hydrophobic Properties Evaluation of Atmospheric Plasma Sprayed NiTi Coating". Thesis, 2022. http://ethesis.nitrkl.ac.in/10404/1/2022_PhD_BKSwain_516MM1011_Mechanical.pdf.
Texto completoKumar, Sanjeet. "Development of ceramic coating on AZ91 alloy for tribological and biomedical applications". Thesis, 2017. http://localhost:8080/xmlui/handle/12345678/7607.
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