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Chen, Qingyuan. "An experimental study of air entrainment in a blade coating system with a pressurised pond applicator." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/5807.
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Deblais, Antoine. "Etalement de fluides complexes." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0303/document.
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Ce travail de thèse porte sur l'étalement de fluides complexes. Il met en évidence la riche phénoménologie d'un acte simple : celui d'étaler avec un racloir (rigide ou souple) une émulsion ou une solution de polymères sur un substrat. Pour chacun des fluides modèles étudiés, nous nous sommes focalisés expérimentalement sur l'observation de l'écoulement au cours de l'entraînement de la solution. Dans des conditions données d'étalement, il apparaît qu'une émulsion o/w peut s'inverser via plusieurs mécanismes de déstabilisation, ou encore, dans le cas d'une solution de polymères, exhiber une instabilité de sa ligne de contact, donnant naissance à des filaments de tailles et de longueurs d'ondes spécifiques. Nous montrons que les différents paramètres d'étalement, comme par exemple la hauteur du racloir, la vitesse d'étalement, les propriétés du substrat ou encore la rhéologie des solutions, doivent être pris en compte pour construire des diagrammes de phase d'étalement séparant les domaines d'existence des instabilités observées (régime de recouvrement partiel), des domaines où la solution transite vers le recouvrement total du substrat. D'autre part, nous tirons l'avantage de ces instabilités pour nous permettre de déposer de façon contrôlée des structures variées, offrant d'intéressantes perspectives en termes d'applicationsThis study shows the rich phenomenology of a simple act : spreading complex solutions such as emulsion and polymer solution on a plate, by using a rigid and flexible blade respectively. Here, we experimentally study the flow of the solution over the course of its spreading. During the spreading and in certain conditions, different phenomena occur, namely, emulsion inversion in the case of o/w emulsion or a contact line instability in the case of the polymer solution, which gives rise to the formation of polymer filaments with a well-defined wavelength and characteristic sizes. We showed, thanks to spreading phase diagrams, that the the existence of the instability (partial wetting regime) is separated to a domain where the solution cover the substrate. Spreading parameters such as the height of the scraper, spreading velocity or properties of the fluids turns out to be crucial. Finally, we take advantage of the instabilities to print a variety of interesting patterns for further applications
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Cardoso, Lilian Soares. "Aplicação de transistores orgânicos na fabricação de inversores lógicos digitais." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/18/18158/tde-21032017-153241/.
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Esta tese tem por objetivo o desenvolvimento de metodologias eficientes e de baixo custo para ajustar as propriedades elétricas de OFETs de canal p e de canal n, a fim de possibilitar a fabricação do circuito complementar orgânico, semelhante a uma estrutura CMOS. O desempenho do circuito complementar fabricado foi otimizado, e também foi confeccionado por impressão um OFETs de canal operando em baixas tensões. Para a fabricação do CMOS orgânico foi proposto um método baseado na seleção adequada do solvente da camada dielétrica para ajustar o desempenho elétrico dos OFETs de canal p e de canal n. Os solventes, MEK, nBA e DMSO foram selecionados para a dissolução do PMMA por apresentarem diferenças nos valores de momento de dipolo, de ponto de ebulição e de graus de ortogonalidade em relação as camadas semicondutoras de P3HT e de P(NDI2OD-T2) dos OFETs. A análise dos resultados dos OFETs de canal p e de canal n demonstrou que a metodologia proposta é adequada tanto para o ajuste das propriedades elétricas destes dispositivos quanto para a otimização do desempenho dos mesmos. Os melhores desempenhos elétricos para os OFETs de canal p e de canal n foram obtidos quando utilizados o DMSO e o MEK como solventes do PMMA, respectivamente, devido à perfeita ortogonalidade destes solventes em relação às camadas semicondutoras. Os OFETs de canal p que utilizaram o DMSO e os OFETs de canal n que utilizaram o nBA foram os que apresentaram desempenhos elétricos semelhantes, sendo portanto aplicados na fabricação do CMOS. Valores de ganho entre 6,8 e 7,8 e de margem de ruído entre 28,3 V e 34,5 V foram obtidos para inversores complementares fabricados nesta etapa do trabalho. OFETs de canal p utilizando uma blenda de PTAA: diF TES ADT como camada semicondutora, o PEDOT:PSS como eletrodos dreno/fonte e o P(VDF-TrFE-CFE) como camada dielétrica também foram fabricados neste trabalho. A técnica de blade-coating foi utilizada para a deposição dos eletrodos dreno/fonte e da camada semicondutora, ao passo que a técnica de spray-coating foi utilizada para a deposição da camada dielétrica. Da análise dos resultados foi possível inferir que a utilização de um dielétrico com elevada constante dielétrica (K), como o P(VDF-TrFE-CFE), possibilita o funcionamento dos transistores a baixas tensões (≤ 8 V), porém com valores de mobilidade reduzidos devido à elevada desordem dipolar na interface provocada por este dielétrico. Para minimizar esses efeitos, uma fina camada de um polímero fluorado foi depositada entre a camada semicondutora e a dielétrica pela técnica de blade-coating, constituindo assim uma bicamada dielétrica nos OFETs. Dos resultados das medidas elétricas dos OFETs constituídos pela bicamada dielétrica foi observada permanência do funcionamento destes dispositivos a tensões inferiores a 8 V com desempenho elétricos superiores a resultados já publicados na literatura. Por fim, inversores lógicos unipolares com transistores de carga foram fabricados com os OFETs que utilizaram a bicamada dielétrica, sendo obtidos valores de ganho entre 1,2 e 1,6 e de margem de ruído entre 56% e 68,5% de ½ VDD.This thesis aimed to develop an efficient and low cost method to adjust the electrical properties of p- and n-channel OFETs to allow us to build an organic CMOS and the optimization of printed p-channel OFETs to work at low voltages. We proposed a method to fabricate the organic CMOS, based on the careful selection of dielectric solvent, which was adjusted to obtain the best performance of p- and n-channel OFETs. The dielectric solvents as MEK, nBA and DMSO were selected to dissolve the PMMA dielectric polymer due their different physical properties as dipole moment and boiling point and because they showed slightly different degrees of orthogonality to the P3HT and P(NDI2OD-T2) semiconductor layers of the OFETs. The results showed that the careful selection of the dielectric solvent not only allows to tune the electrical characteristics of the p- and n-channel OFETs, but also to improve the performance of these devices. The best performances were achieved when DMSO and MEK were used as dielectric solvents of the p and n-channel OFETs, respectively, as result of the perfectly orthogonality of these solvents to the semiconductor layers. P-channel OFETs using DMSO and n-channel OFETs using nBA showed similar electrical characteristics and thus, they were used to construct the organic CMOS. The organic complementary inverters showed high gain and noise margin values in the range of 6,8 to 7,8 and 28,3 V to 34,5 V, respectively. Printed p-channel OFETs were also fabricated, in which the blend PTAA:diF TES ADT was used as semiconductor channel, PEDOT:PSS as the drain/source electrodes and P(VDF-TrFE-CFE) as the dielectric layer. The blade-coating technique was used to deposit the source/drain electrodes and the semiconductor layer, while the spray-coating technique was used to deposit the dielectric layer. It was observed that using high-k dielectric as P(VDF-TrFE-CFE) enable to reduce the operating voltage of the OFETs (≤8 V), however, this high-k dielectric also reduced the field effect mobility due the dipolar disorder at the semiconductor/dielectric interface. To minimize the dipolar issue at the interface, we inserted a thin fluoropolymer dielectric layer by blade-coating between the semiconductor and the high-k dielectric layers, thus constituting a dielectric bilayer on the OFETs. From the electrical measurements of the OFETs with the dielectric bilayer, it was observed that the devices were still working at 8 V and they also showed better performance in comparison to results already published. Finally, organic unipolar inverters with load transistors were fabricated using the p-channel OFETs with the dielectric bilayer and they showed reasonable performance, with gain and noise margin in the range of 1,2 to 1,6 and 56% e 68,5% of ½ VDD, respectively.
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Maillard, Mathilde. "Étalements de fluides à seuil." Thesis, Paris Est, 2015. http://www.theses.fr/2015PESC1111/document.
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Les fluides à seuil sont des matériaux utilisés dans de nombreux procédés industriels au cours desquels ils sont mis en écoulement via leur interaction avec des outils solides. Afin de mieux comprendre comment ils s'étalent sur des surfaces, nous avons étudié d'une part leur enduction verticale sur une plaque mince et d'autre part leur étalement horizontal à l'aide d'une lame. Ces deux études se sont appuyées sur des mesures macroscopiques permettant de suivre la force appliquée à l'outil et des mesures microscopiques de PIV pour déterminer les champs de vitesse dans le matériau. Après confirmation de leur validité par comparaison avec nos résultats expérimentaux, des simulations numériques basées sur la programmation conique ont permis de préciser les écoulements en jeu. Pour l'enduction par trempage, nous observons que dans notre gamme d'étude, le dépôt de fluide à seuil sur la plaque est millimétrique et d'épaisseur constante, sauf aux extrémités. Selon le rapport des forces visqueuses et plastiques, l'enduction est régie par un équilibre "seuillo-gravitaire" ou "visco-gravitaire". Nous avons ensuite caractérisé l'écoulement généré dans le bain par le déplacement de la plaque afin d'expliciter l'origine du phénomène d'enduction. Les simulations numériques précisent la forme de cet écoulement. L'étalement horizontal dans un canal à l'aide d'une lame mince conduit au déplacement d'un amas de fluide faiblement cisaillé par rapport à une région de fluide au repos, par l'intermédiaire d'une couche cisaillée. Nous montrons qu'un modèle simple permet de prédire la dynamique de croissance de l'amas et la relie à la force normale à la lameYield stress fluids are used in various industrial processes in which solid tools make them flow. To have a better understanding on how they spread on surfaces, we first studied the vertical coating on a thin plate and then the horizontal blade-coating. Both studies are based on macroscopic measures recording the force applied on the plate and on the microscopic determination on the velocity fields in the fluid by PIV. Numerical simulations based on cone programming, which validity had been confirmed in comparison to our experimental results, specified the flows at stake. In dip-coating, we observed than within our framework, the yield stress fluid deposit on the plate is millimetric and of constant thickness, except on the tips. According to the value of the viscous over plastic forces ratio, the coating is led by a "yield-gravity" or a "visco-gravity" balance. Then, we characterized the flow generated in the bath by the plate displacement in order to clarify the origin of the coating phenomenon. The numerical simulations specified the flow characteristics. The horizontal blade-coating in a channel involves the displacement of a weakly sheared cluster of fluid in relation to a part of fluid at rest, through a sheared layer. We showed that the growing dynamic of the cluster is described with a simple model which links it to the normal force to the plate
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Van, Dyke Jason. "Modeling Behaviour of Damaged Turbine Blades for Engine Health Diagnostics and Prognostics." Thèse, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/20312.
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The reliability of modern gas turbine engines is largely due to careful damage tolerant design a method of structural design based on the assumption that flaws (cracks) exist in any structure and will continue to grow with usage. With proper monitoring, largely in the form of periodic inspections at conservative intervals reliability and safety is maintained. These methods while reliable can lead to the early retirement of some components and unforeseen failure if design assumptions fail to reflect reality.
With improvements to sensor and computing technology there is a growing interest in a system that could continuously monitor the health of structural aircraft as well as forecast future damage accumulation in real-time.
Through the use of two-dimensional and three-dimensional numerical modeling the initial goals and findings for this continued work include: (a) establishing measurable parameters directly linked to the health of the blade and (b) the feasibility of detecting accumulated damage to the structural material and thermal barrier coating as well as the onset of damage causing structural failure.
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Hey, Andrew Stuart. "Series interconnects and charge extraction interfaces for hybrid solar cells." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:f19e44a8-e394-4859-9649-734116bc22b8.
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This thesis investigates novel hole extraction interfaces and series interconnects for applications in organic photovoltaics, specifically in single junction solid-state dye-sensitized solar cells (DSSCs) and tandem DSSC/polymer bulk heterojunction solar cells. Improvements in hole extraction and device performance by using materials compatible with scalable deposition methods are presented, including tungsten- and molybdenum-disulphide (WS2 and MoS2), and p-type doped spiro-OMeTAD (2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)9,9'-spirobifluorene) nanoparticle dispersions. WS2 and MoS2 hole extraction layers increase averaged short circuit currents by 20% and 16% respectively, and power conversion efficiencies by 19% and 14% respectively when compared with control devices. Similarly, doped spiro-OMeTAD nano-particle layers improved short circuit current densities by 32% and efficiencies by 9%. Tandem device interconnects using these novel hole extraction formats have been fabricated, but although devices did exhibit rectification, overall performance was poor. Possible reasons for their limited success have been analysed. Dye-sensitized solar mini-modules are also reported. In order to assure the scalability of DSSC technology, these larger area devices were constructed using doctor blade coating to deposit the hole transporter material. As well as achieving a respectable maximum power conversion efficiency of 2.6%, it has also been shown that the extent to which hole transporter infiltrates the mesoporous photoanode of these devices may be tuned by altering substrate temperature during deposition. It was found that an optimal coating temperature of 70 degrees C produced the best efficiency, with a corresponding pore-filling fraction of 41%.
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Long, K. "Aluminide-based coatings for turbine blade internal cooling passages." Thesis, Cranfield University, 2004. http://dspace.lib.cranfield.ac.uk/handle/1826/11002.
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The development of aero-gas turbines is moving towards more efficient engines
with higher pressure ratios and increased Turbine Entry Temperatures. This leads to
increases in overall turbine blades temperatures which has resulted in the widescale
development of turbine blades with film cooling and Thermal Barrier Coatings (TBCs)
which reduce the metal temperature of the blade. The air used for film cooling is
directed around the blade by internal passages within the blade, current engines are
experiencing hot corrosion in areas of these internal passages, even with internal
aluminide coatings. The trend for more efficient engines means that corrosion of the
internal passages will become more common, coupled with the inability to inspect the
internal passages of turbine blades in service, results in a requirement for an improved
coating for the internal passages of turbine blades.
The aim of this study was to develop a coating which provides improved
corrosion and oxidation performance over a standard vapour aluminide on single crystal
CMSX-4 turbine blades material. The coating needs to be compatible with the Rolls-
Royce bond coat and the Rolls-Royce manufacturing strategy.
The study investigated a number of additions which could be used to
improve the performance of an aluminide coating. Silicon was selected as the optimum
addition on the basis of performance and ease of deposition. The work then assessed the
influence of various production parameters on the formation of a silicon-aluminide
coating. It was possible to control the level of silicon deposited in the coating.
Performance testing, using cyclic oxidation and salt recoat hot corrosion
tests, of various silicon aluminides developed in this programme demonstrated at least a
doubling in life compared with vapour aluminide coatings.
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Rakotomalala, Noémie. "Simulation numérique de l’écaillage des barrières thermiques avec couplage thermo-mécanique." Thesis, Paris, ENMP, 2014. http://www.theses.fr/2014ENMP0020/document.
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L'objectif de ce travail de thèse est de mettre en place une simulation thermo-mécanique couplée d'une aube revêtue permettant de modéliser l'écaillage de la barrière-thermique qui survient dans les conditions de service de l'aube. La barrière thermique est un revêtement isolant déposé à la surface du substrat monocristallin base Nickel AM1 constitutif de l'aube préalablement recouverte d'une sous-couche. Le mode de dégradation dominant dans ces systèmes est la création de fissures qui résultent de l'accroissement des ondulations hors-plan d'une couche intermédiaire d'oxyde formée en service entre la céramique et la sous-couche. En vue de modéliser ce phénomène d'écaillage, un ensemble d'outils numériques permettant de réaliser un calcul 3D par éléments finis thermo-mécanique couplé de l'aube revêtue est développé au sein du code de calcul par éléments finis Z-set. L'insertion d'éléments de zone cohésive mécanique et thermique au niveau de l'interface barrière-thermique/substrat permet de tenir compte simultanément des changements dans le processus de transert de charge et des variations du flux de chaleur causés par l'amorçage et la propagation d'une fissure interfaciale. L'élément fini d'interface mixte de Lorentz qui repose sur un Lagrangien augmenté, est mis en oeuvre. Afin de tenir compte des propriétés structurelles du revêtement, la modélisation de la barrière thermique est réalisée au moyen d'éléments de coque thermo-mécaniques reposant sur l'approche dite “Continuum Based”. Ces éléments sont développés puis validés dans le cadre de la thèse. La méthode utilisée pour réalier le couplage thermo-mécanique est l'algorithme partitioné CSS (Conventional Serial Staggered) sous-cyclé à pas de couplage fixe dont on montre les limitations dans le cas d'une simulation impliquant la propagation d'une fissure. L'introduction de pas de couplage adaptatifs contrôlés au moyen d'une variable interne du problème mécanique a permis de contourner ces limitations. L'ensemble des briques numériques est validé sur des cas tests de complexité croissante. Des cas d'applications effectués sur des géométries tubulaires à gradient thermique de paroi sont réalisés afin de tester le modèle couplé sur des structures et des chargements proches des conditions de service de l'aube. Enfin, des calculs thermo-mécaniques couplés sur aube revêtue sont présentésThe purpose of this thesis is to perform a coupled thermomechanical simulation of the failure of thermal barrier coatings for turbine blades under service conditions. The thermal barrier coating is an insulating component applied to the single crystal Nickel-based superalloy AM1 substrate which is covered with a bond coat beforehand. The main degradation mode of those systems is due to the initiation and propagation of cracks caused by the out-of-plane undulation growth of an oxide layer formed in service. A set of numerical tools is implemented into the Finite Element code Z-set in order to perform a 3D thermomechanically coupled simulation of the failure of thermal barrier coatings for turbine blades. Inserting thermomechanical cohesive zone elements at the interface between the coating and the substrate makes it possible to account for the changes in the load transfer and the variations in the heat flux as a consequence of interface degradations. The mixed finite interface element of Lorentz based on an Augmented Lagrangian is used. The thermal barrier coating is modelled by means of thermomechanical shell elements implemented using the Continuum-Based approach to take advantage of the structural properties of the coating layer. Moreover, the partitionned CSS (Conventional Serial Staggered) algorithm used to couple thermal and mechanical problems is assessed. The limitations of sub-cycling with constant coupling time-step are shown through a simulation with crack propagation. The introduction of adaptative time-stepping allows to circumvent that issue. The numerical tools are assessed on test cases with increasing complexity. Numerical simulations on cylindrical tube with a thermal through-thickness gradient are performed with realistic loading sequences. Finally, thermomechanical simulations on turbine blades covered with thermal barrier coating are shown
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Khan, Fahd. "Investigating into advanced coatings for bandsaw blades." Thesis, Northumbria University, 2011. http://nrl.northumbria.ac.uk/36301/.
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Bandsawing is an important metal cutting operation carried out in a variety of industries in order to remove raw material for secondary operations. Due to its continuous cutting action, bandsawing has over taken other cutting processes such as power hack sawing and circular sawing. Bandsawing operation offers numerous advantages such as high cutting rate, low kerf loss, longer tool life and high automation possibilities, due to its efficient and continuous cutting action. It is costly and time-consuming to test the wear of the full bandsaw products on a full-scale bandsaw machine. In order to overcome this, a single tooth test rig has been developed at Northumbria University, which utilizes a single bandsaw tooth instead of the complete bandsaw loop. Previous research has utilized this test rig for evaluating bi-metal saws while machining steels. Development of new, wear resistant and difficult-to-cut materials such as titanium alloys (e.g. Ti-17) imposes greater demands on bandsawing operations. Traditionally, high speed steels and cemented carbides have been employed to cut/machine these materials. The main disadvantage of high speed steel cutting tools is that it undergoes severe plastic deformation when cutting at temperatures above 600oC. Tungsten carbide cutting tools have proven their supremacy in almost all the machining processes and interrupted cutting of these difficult-to-cut titanium alloys. One of the challenges in design of cemented tungsten carbide tools is the optimization of toughness and wear resistance. This has led to the development of coated carbide tools, which accounts for the major portion of all commercial metal cutting inserts sold worldwide. This current research has furthered the use of single tooth test rig, by using un-coated and coated tungsten carbide tipped bandsaw blades while machining high performance titanium alloys (Ti-17). The purpose is to evaluate and assess the performance of un-coated and coated carbide bandsaw teeth and ascertain wear mechanisms and modes of single bandsaw tooth, in a way that is representative of full product testing. Two different coatings (AlTiN and TiAlSiN) were chosen to be deposited using arc evaporation PVD technique. These coatings were selected due to their properties in terms of wear resistance and structure: TiAlSiN is nano-structured, while AlTiN is conventional in terms of its grain size. These coatings were characterized using various techniques, such as electron microscopy and nano-indentation. Cutting tests were carried out using un-coated and coated carbide bandsaw teeth. Adhesive wear and diffusion wear were identified as the wear mechanisms, while flank wear and chipping were confirmed as the principal wear modes for the un-coated carbide bandsaw teeth. Cutting forces were found to be less while machining Ti-17 alloy using coated teeth as compared to the forces obtained while machining with un-coated teeth. Less material was found to be adhering to the coated teeth as compared to un-coated teeth. Finite element analyses (FEA) were carried out on interaction of the cutting tool and the workpiece to determine the stress concentration during the cutting process. It was found that the increase in the honing lengths on the carbide teeth reduced the stresses and moved the maximum stress from the edge of the rake face to the honed edge.
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Chien, H. H. "The mechanical properties of aluminide coatings." Thesis, Cranfield University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.352970.
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Vincent, Julien. "Étude expérimentale des interactions aube-abradable à très grandes vitesses : influence du matériau et de sa microstructure." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0334.
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Le rendement des turboréacteurs peut être amélioré en minimisant le jeu aube-carter, réduisant ainsi les pertes aérodynamiques. Ces jeux réduits occasionnent des risques de contact entre les aubes en rotation à grande vitesse et le carter moteur. Des matériaux sacrificiels, appelés matériaux abradables, sont alors déposés sur le carter pour limiter les endommagements induits par ces contact. Ces interactions font intervenir un grand nombre de mécanismes d’endommagement bénéfiques ou néfastes au bon fonctionnement du joint abradable et à la fiabilité du moteur. L’objectif de cette thèse est alors de comprendre, prédire et quantifier les différents endommagements et les efforts d’interaction associés pour des matériaux abradables obtenus à l’aide de paramètres procédés différents. Un dynamomètre triaxial a été développé afin de reproduire l’interaction locale entre l’extrémité de l’aube et le matériau abradable à très grande vitesse (50 – 300 m/s) lors de phases transitoires. La mesure d’efforts d’interaction lors de contacts de très courte durée (300 µs – 1 ms) nécessite une bande passante importante. Une méthode de correction basée sur l’analyse modale expérimentale a été mise en œuvre afin d’étendre la bande passante naturelle du dynamomètre et d’atténuer les couplages entre les différentes voies de mesure. Les mécanismes d’endommagements des abradables ont été étudiés à partir d’analyses post-mortem et corrélés aux efforts et vitesse d’interactionsThe turbofan efficiency can be improved by minimizing the blade-casing gap, thus reducing the aerodynamic loss. The reduced gap conduces to contact risk between the high-speed rotating blades and the engine case. Sacrificial materials, called abradable materials, are deposited on the casing to limit the damage caused by these contacts. These interactions involve a lot of damage mechanisms, which can be adverse or beneficial to the proper performance of the abradable seal and to the reliability of the engine. The aim of this thesis is to understand, predict and quantify the different damages and the interaction forces associated for abradable materials obtained with different process parameters. A triaxial dynamometer was developed to reproduce the local high-speed interactions (50 – 300 m/s) between the blade tip and the abradable material during transitional phases. The interaction forces measurement during short-lived contacts (300 µs – 1 ms) requires a large bandwidth. A correction method based on experimental modal analysis was implemented to extend the natural bandwidth of the device and attenuate the crosstalk between the different measurement channels. The damage mechanisms of abradable materials were studied by post-mortem analysis and correlated to the interaction forces and velocity
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Mandard, Romain Baptiste. "Dynamique de contact aube- revêtement abradable : identification expérimentale de la force et des mécanismes d'interaction." Thesis, Ecole centrale de Lille, 2015. http://www.theses.fr/2015ECLI0001.
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Le rendement des compresseurs aéronautiques est amélioré en minimisant le jeu entre les aubes en rotation et le carter qui les entoure, réduisant ainsi les fuites aérodynamiques. Ce jeu réduit occasionne des contacts entre les aubes et le carter ; afin d’assurer leur intégrité mécanique, le carter est revêtu d’un matériau abradable sacrificiel, lequel accommode les incursions d’aube. Les interactions aube – revêtement abradable couplent des phénomènes tribologiques et vibratoires à haute vitesse et à haute température, dont l’étude expérimentale est requise pour le développement de modèles numériques prédictifs. L’objectif de cette thèse est d’identifier expérimentalement la force et les mécanismes d’interaction aube-abradable AlSi-Polyester dans une configuration d’essai représentative du fonctionnement des étages de compresseur basse-pression. Des méthodes couplées expérimentales - analytiques, prenant en compte la dynamique d’aube, ont été développées afin d’accéder à la force d’interaction et à l’incursion aube-abradable. L’influence de la température, de la nuance du matériau abradable et de la raideur d’aube a été étudiée. Les mécanismes d’usure et d’endommagement du revêtement abradable ont été investigués et corrélés aux conditions d’interaction. Ces travaux de thèse ont été réalisés dans le cadre d’une collaboration entre le Laboratoire de Mécanique de Lille, SNECMA Villaroche (groupe SAFRAN) et le centre ONERA de LilleMinimizing the clearance between turbofan blades and the surrounding casing is a key factor to re-ducing leakage flows and consequently improving efficiency. The tight clearance may lead to blade-casing interactions. An abradable coating is deposited on the casing to accommodate blade incursions and thus to protect the blades and the casing from severe damage. Blade/abradable-coating interactions involve tribological and vibratory phenomena at high velocity and temperature. Experimental knowledge of these interactions is paramount to the proper design of abradable materials and the prediction of their lifetimes through numerical simulations. The purpose of this thesis is to identify experimentally the force and the mechanisms occuring during interaction between a vibrating blade and an AlSi-Polyester abradable coating. To this end, experiments were conducted on a dedicated test rig, in conditions representative of low-pressure compressor situation. Specific methods involving dynamical measurements and analytical models have been developed in order to obtain the blade/abradable-coating interacting force as well as the blade tip incursion. The influence of temperature, coating nature and blade stiffness has been studied. The interaction mechanisms and wear of the abradable coating have been investigated and correlated with the interaction conditions. This work was achieved within the framework of cooperation between Laboratoire de Mécanique de Lille (France), SAFRAN-SNECMA (France) and ONERA, the French Aerospace Lab
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Hook, Matthew Simon. "The effects of high temperature oxidation and exposure on nickel-base superalloys and turbine blade coatings." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.615949.
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Nemetz, Wolfgang [Verfasser]. "Chemical Vapour Deposition of Thermal Barrier Coatings on Turbine Blades / Wolfgang Nemetz." Aachen : Shaker, 2005. http://d-nb.info/1186580844/34.
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Hoque, Abdul. "Bonding mechanisms in the application of thermal barrier coatings to turbine blades." Thesis, Sheffield Hallam University, 2004. http://shura.shu.ac.uk/19825/.
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Thermal barrier coatings (TBC's) are used to protect gas turbine blades from environmental degradation as well as to increase thermodynamic efficiency. Most TBC systems consist of a ceramic thermal barrier coating such as partially stabilized zirconia adhering to an oxidation resistant bond coat, which in turn is bonded to the turbine blade. This is required since partially stabilised zirconia will not readily bond to superalloys. However, the TBC can fail in service either by bond coat oxidation or thermal expansion mismatch between the bond coat and the TBC. A systematic literature survey has shown that the superalloy substrate material, type of bond coat selected, with the coating application techniques i.e. thermal spray or Electron Beam PVD (EBPVD) plays a fundamental role in determining the failure mechanisms involved. This program of work is concerned with the development of coatings with enhanced temperature capabilities for turbine blade applications by understanding the fundamental mechanisms responsible for adhesion between the nickel based turbine blade and zirconia based TBC. An understanding of the bonding mechanisms will allow the design of advanced coating systems with increased operating temperatures. This program of work introduces the Glow Discharge Optical Emission Spectroscopy (GDOES) technique, an atomic emission technique used for both bulk and depth profile analysis, which had not previously been applied to TBC's, and SEM and TEM in order to enhance understanding of failure modes in TBC systems and adhesion process. The results obtained from the studies indicate that the GDOES technique can be applied to depth profile bond coats and exposed TBC systems both qualitatively and semi-quantitatively. GDOES has been able to detect elements such as silicon and sodium that are in the ppm levels which are difficult/impossible to detect using EDX systems, and are very important in coating developments. In addition, as a preliminary guide GDOES has shown Ti diffusion from the superalloy substrate into the bond coat to be detrimental towards coating adhesion on most of the systems studied. The results of SEM and cross-sectional TEM on selected bond coat systems has shown the low cost Pt bond coat microstructure system to consist of TBC, Al2O3 bond coat and CMSX-4 superalloy substrate in all cases. The intermediate layer between the TBC and bond coat consists of Al2O3 which has been identified as responsible for maintaining the adhesion. Also identified is evidence of Ti segregation at the Al2O3/bond coat interface, known to lead to decohesion in coatings. Failure in the low cost Pt bond coat system has been identified as the decohesion between the interfacial layer of Al2O3 and the bond coat. The program of studies has enabled failure mechanisms and factors affecting bonding to be identified in low cost Pt bond coat systems, so that in future better coating systems with enhanced properties can be designed This should also ensure that improved reliability in engines and increased service life of turbine blades be achieved.
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Hocquette, Disdier Hélène. "Etude structurale de revetement de surface amorphe métallique élaboré par chalumeau plasma." Université Joseph Fourier (Grenoble), 1995. http://www.theses.fr/1995GRE10016.
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Le but de cette these est l'etude structurale de revetements de surface par un depot amorphe metallique qui ont pour application la protection d'aubes de turbines hydrauliques. Les depots sont elabores par la technique du chalumeau plasma sous atmosphere et temperature controlees. La caracterisation structurale est faite principalement par microscopie electronique en transmission conventionnelle et haute resolution, ainsi que par microanalyse x. Une premiere partie presente les proprietes des verres metalliques et valide le choix de tels materiaux pour l'application industrielle envisagee. La demarche suivie pour le choix de la composition du depot est egalement decrite. Le deuxieme chapitre est consacre a la presentation du procede d'elaboration et des techniques experimentales mises en uvre. Les resultats experimentaux, a partir d'echantillons modeles et industriels obtenus pour differentes conditions d'elaboration, sont presentes dans le troisieme chapitre. Ils mettent l'accent sur certains artefacts produits par la technique d'observation, et mettent en evidence des effets de la methode d'elaboration sur l'etat structural des echantillons. L'analyse et l'interpretation de ces resultats faites dans le dernier chapitre, permettent une approche des mecanismes d'adherence depot/substrat de ces echantillons. Un protocole est enfin propose pour une meilleure qualite des revetements
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Eriksson, Amanda, and Simon Reinberth. "Influence of thermal barrier coating and cooling flow on turbine blades : Impact of manufacturing tolerances on life assessments." Thesis, Linköpings universitet, Mekanik och hållfasthetslära, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-166377.
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Mukherjee, Sriparna. "Evolution of microstructure and residual stress in disc-shape EB-PVD thermal barrier coatings and temperature profile of high pressure turbine blade." Master's thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4989.
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A detailed understanding of failure mechanisms in thermal barrier coatings (TBCs) can help develop reliable and durable TBCs for advanced gas turbine engines. One of the characteristics of failure in electron beam physical vapor deposited (EB-PVD) TBCs is the development of instability, named rumpling, at the interface between (Ni, Pt)Al bond coat and thermally grown oxide (TGO). In this study, thermal cycling at 1100[degrees]C with 1 hr dwell time was carried out on 25.4mm disc specimens of TBCs that consisted of EB-PVD coated ZrO[sub2]-7wt.%Y[sub2]O[sub3], (Pt,Ni)Al bond coat, and CMSX-4 Ni-based superalloy. At specific fraction of lifetime, TBCs were examined by electron microscopy and photostimulated luminescence (PL). Changes in the average compressive residual stress of the TGO determined by PL and the magnitude of rumpling, determined by tortuosity from quantitative microstructural analyses, were examined with respect to the furnace thermal cyclic lifetime and microstructural evolution of TBCs. The combination of elastic strain energy within the TGO and interfacial energy at the interface between the TGO and the bond coat was defined as the TGO energy, and its variation with cyclic oxidation time was found to remain approximately constant ~135J/m[super2] during thermal cycling from 10% to 80% thermal cyclic lifetime. Parametric study at ~135J/m[super2] was performed and variation in residual stress with rumpling for different oxide scale thicknesses was examined. This study showed that the contribution of rumpling in residual stress relaxation decreased with an increase in TGO thickness. High pressure turbine blades serviced for 2843 hours and in the as coated form were also examined using electron microscopy and photostimulated luminescence. The difference in residual stress values obtained using PL on the suction and pressure sides of as-coated turbine blade were discussed.; The presence of a thick layer of deposit on the serviced blade gave signals from stress free alpha]-Al[sub2]O[sub3] in the deposit, not from the TGO. The TGO growth constant data from the disc-shape TBCs, thermally cycled at 1100??C, and studies by other authors at different temperatures but on similar EB-PVD coated TBCs with (Pt, Ni)Al bond coat and CMSX-4 Ni- based superalloy were used to determine the temperature profile at the YSZ/bond coat interface. The interfacial temperature profiles of the serviced blade and the YSZ thickness profile were compared to document the variable temperature exposure at the leading edge, trailing edge, suction and the pressure side.ID: 030423389; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.)--University of Central Florida, 2011.; Includes bibliographical references (p. 90-92).
M.S.
Masters
Mechanical, Materials, and Aerospace Engineering
Engineering and Computer Science
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Coste, Jean-François. "Détermination non destructive de l'épaisseur de revetements projetés plasma au moyen d'ondes de surface rayonnantes." Grenoble INPG, 1996. http://www.theses.fr/1996INPG4202.
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Les revetements metalliques deposes par projection plasma sous vide sur les pales de turbines a gaz ameliorent leur resistance a la corrosion et augmentent ainsi leur duree de vie. Cependant, le controle de qualite et l'inspection en service de ces pales revetues consistent simplement en une inspection visuelle et en un examen micrographique destructif. Pour ces raisons, les fabricants et les utilisateurs de turbines a gaz deploient un effort important pour le developpement de techniques non destructives. L'epaisseur du revetement represente un parametre d'interet puisqu'il caracterise l'efficacite du depot. Une technique non destructive, basee sur la propagation des ondes de surface, a ete mise au point et utilisee pour caracteriser les materiaux pour pales de turbine a gaz. Cette technique par immersion utilise deux traducteurs large bande fonctionnant en transmission et en mode impulsionnel. Lors d'une premiere etape, les variations de l'amplitude et de la phase du signal sont enregistres au fur et a mesure que les traducteurs sont translates perpendiculairement a la surface de l'echantillon. Ces parametres sont simplement lies a la vitesse et a l'attenuation des ondes de surface. Dans un second temps, l'epaisseur est deduite de la comparaison entre la variation de l'un des parametres mesures en fonction de la frequence et une expression theorique. Celle-ci est obtenue en se basant soit sur la difference entre les constantes elastiques du substrat et du revetement, soit sur la difference entre leurs microstructures
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Lokachari, Siddharth [Verfasser], and Donald Bruce [Akademischer Betreuer] Dingwell. "Thermo-mechanical degradation and mitigation of molten volcanic ash wetting on thermal barrier coatings of jet engine turbine blades / Siddharth Lokachari ; Betreuer: Donald Bruce Dingwell." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2020. http://d-nb.info/122152447X/34.
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Lokachari, Siddharth [Verfasser], and Donald Bruce [Akademischer Betreuer] Dingwell. "Thermo-mechanical degradation and mitigation by molten volcanic ash wetting on thermal barrier coatings of jet engine turbine blades / Siddharth Lokachari ; Betreuer: Donald Bruce Dingwell." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2020. http://nbn-resolving.de/urn:nbn:de:bvb:19-270381.
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Lin, Hung-Wei, and 林鴻維. "Automatic delivery by blade coating." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/8bntgd.
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Pan, Chien-Hua, and 潘建樺. "Mechanochromic Macroporous Photonic Crystals by Doctor Blade Coating." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/2jk69u.
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碩士國立中興大學
化學工程學系所
106
In this research, silica colloidal crystals/aliphatic urethane acrylate (PUA)/ethoxylated trimethylolpropane triacrylate (ETPTA) polymer composites were continuously prepare by a simple, roll-to-roll compatible doctor blade coating technology using three different silica particle sizes (370 nm, 330 nm and 255 nm). After photocuring, the colloidal crystals in the polymer composites are removed by wet chemical etching to obtain the mechanochromic macroporous films. The macroporous structure is three-dimensional and hexagonal close-packed. The films with three different pore sizes can be prepared from three different silica particle sizes, and three macroporous films respectively diffract light by three different photonic band gaps to present different colors. The stretched films can change the lattice spacing and have a mechanism of color change. The 370 nm mechanochromic macroporous film appears red. During the slow stretching, the color gradually changes from red to green from 0 to 50 % elongation. The 330 nm mechanochromic macroporous film appears yellow. From 0 to 50 % elongation, its color gradually changes from yellow to blue. Interestingly, the 255 nm mechanochromic macroporous film exhibits purple. From 0 to 50 % elongation, its color can be gradually changed from purple to colorless. This research has successfully achieved a color-to-colorless effect. Moreover, the color changes of three mechanochromic macroporous films are reversible and can repeat this stretching process at least ten times in the same conditions.
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Wang, Chun-Min, and 王俊閔. "High efficiency Organic solar cells by blade coating method." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/28824546181992054526.
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碩士國立交通大學
物理研究所
101
Blade coating method has been successfully applied to the bulk heterojunction organic solar cells，and the efficiency of the solar cell by blade coating method can be equivalent to the spin-coating slow drying process. We use the heater and hot air so that the solution to dry.The organic layer of the blade coating rapid drying in a short time. with the traditional spin - coating slow drying process comparison, this way not only can improve material utilization and can reduce the process time. Therefore this process by an extension of materials used in high efficiency and lower toxicity of toluene as a solvent, in an attempt to develop a low toxicity and can be mass-produced organic solar cell process.
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Hong, Shi-Hui, and 洪詩惠. "Photonic Crystals-Based Smart Glasses by Doctor Blade Coating." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/09128782989487479431.
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碩士國立中興大學
化學工程學系所
105
A simple, roll-to-roll compatible doctor blade coating technology for producing three-dimensional highly ordered macroporous polymer membranes is developed. The research describes an invention in using the prepared macroporous polymer films as photonic crystals for large area, low cost, and no energy consumption self-adjusting smart glasses, which are useful for energy control in glazed buildings. This invention is inspired by the heat pipe technology. When the air cavities are filled with a solvent which has the same refractive index as that of the polymer, the macroporous polymer films become completely transparent due to the index matching. When the solvent trapped in the cavities is evaporated by in-situ heating, the sample color changes back to brilliant color. Therefore, once the amount of solvent trapped in the macroporous films can be automatically controlled by difference between indoor and outdoor temperature, the device can make macroporous film self-adjust light transmission. Moreover, the glass surface exhibits superhydrophobic and self-cleaning properties after surface modification.
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Munir, Rahim. "Hybrid Perovskite Thin Film Formation: From Lab Scale Spin Coating to Large Area Blade Coating." Diss., 2017. http://hdl.handle.net/10754/627190.
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Our reliance on semiconductors is on the rise with the ever growing use of electronics in our daily life. Organic-inorganic hybrid lead halide perovskites have emerged as a prime alternative to current standard and expensive semiconductors because of its use of abundant elements and the ease of solution processing.
This thesis has shed light on the ink-to-solid conversion during the one-step solution process of hybrid perovskite formulations from DMF. We utilize a suite of in situ diagnostic probes including high speed optical microscopy, optical reflectance and absorbance, and grazing incidence wide angle x-ray scattering (GIWAXS), all performed during spin coating, to monitor the solution thinning behavior, changes in optical absorbance, and nucleation and growth of crystalline phases of the precursor and perovskite. The starting formulation experiences solvent-solute interactions within seconds of casting, leading to the formation of a wet gel with nanoscale features visible by in situ GIWAXS. The wet gel subsequently gives way to the formation of ordered precursor solvates (equimolar iodide and chloride solutions) or disordered precursor solvates (equimolar bromide or 3:1 chloride), depending upon the halide and MAI content. The ordered precursor solute phases are stable and retain the solvent for long durations, resulting in consistent conversion behavior to the perovskite phase and solar-cell performance. In this thesis, we develop a firm understanding of the solvent engineering process in which an anti-solvent is used during the coating process through the solvent mixture of GBL and DMSO in different ratios. It has been shown that solvent engineering produce pin hole-free films, justifying its wide adoption across the field. We then translate our learnings from the lab scale spin coating process to the industrial friendly blade coating process. Here we compare the ink solidification and film formation mechanisms of CH3NH3PbI3 in solutions we used to understand the key scientific insights through spin coating. We observe high-quality film formation for T > 100oC, namely in conditions which inhibit the formation of the crystalline intermediate complex phases. In doing so, we achieve fast and direct formation of the perovskite phase with solar cells yielding PCE > 17%.
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Lin, Bor-Jou, and 林柏洲. "Organic solar cells fabricated by blade-coating on flexible substrates." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/04521355916754850354.
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碩士國立清華大學
光電工程研究所
97
Although the power conversion efficiency (PCE) of single layer inorganic solar cells have achieved 24%, the supply of silicon ingredient and the machines of complicated fabrication process are expensive, it might take too much cost while commercializing this method. In contrast, polymer solar cells have attracted great attention because of their unique properties such as simple and cost-effective fabrication process, light weight, and flexibility. Photonic devices on flexible substrates will develop toward large area and tandem construction by using the blade coating which combine with roll-to-roll process. In our work, we blend conjugated polymer P3HT and PCBM as the active layer absorption material. The bulk hetero junction of P3HT and PCBM blending in DCB blade-coated on patterned IZO PC flexible substrates makes the process of exciton diffusion to the charge separation donor-acceptor interface be efficient. Researches demonstrate that PCE of blade-coating applying in flexible organic solar cell with normal and inverted structure has the same or even better result compare with PCE of spin-coating. The highest PCE of normal cell fabricated by blade coating and spin coating are 2.24%.and 2.29% respectively. For inverted structure we have 3.37% for blade-coating and 3.25% for spin-coating. Additionally, it is an advantage that blade-coating can apply to roll to roll continuously fabrication and large area application. According to these reasons, we can expect that blade-coating can replace spin-coating on flexible substrate in the near future.
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Hsin, Chi-Hsueh, and 辛計學. "Development of large-area ultrasonic atomization assisted blade coating process." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/7dy457.
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Huang, Pang-Hua, and 黃邦華. "Large-Area Hybrid PEDOT:PSS/Si Solar Cells Using Blade Coating." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/ppsjak.
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碩士國立交通大學
光電系統研究所
106
Hybrid organic/ silicon solar cells employ low-temperature and solution processes and is compatible to be fabricated on bendable and thin substrates, making them promising candidates for future photovoltaic industry. However, scalability of hybrid solar cells has been limited by the uniformity of the organic thin film. In this work, we have developed a blade coating technique to expand the active area of the hybrid solar cells, from 1x1 cm2 up to 10x10 cm2 while minimizing the power loss upon scaling. First, an carbon-nanotube (CNT) doped poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) is employed as the hole conducting material for its high transparency and conductivity. The properties of CNT-doped PEDOT:PSS against the blade coating speed are tested, followed by the material modifications using surfactant and ethanol. By optimizing the amount of surfactant, we achieve a power conversion efficiency of 13.0% on a 1x1 cm2 device at the 200 nm/sec coating speed. Second, we scale up the cell area to 2x2 cm2 by optimizing the shadow ratio of the frontal silver grid, while controlling the uniformity of the film thickness at proper coating speed. An excellent PCE of 13.5% was achieved on the 2x2 cm2 device using 1wt% surfactant, 10% shadow ratio and 400 mm/s blade coating speed, showing an PCE enhancement factor of 13.4% compared to the spin coating process. Finally the film thickness and blade coating speed have been tested on a 6-inch silicon wafer for therealization of large-area hybrid solar cells. Preliminary results show that a cell with a 10x10cm2 active area exhibits a PCE of 6.9% possibly limited by the Ag grid design.
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Jia-mingLin and 林家名. "Development of large-area Perovskite solar cell by blade coating." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/833dhk.
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碩士國立成功大學
電機工程學系
107
This thesis reports the development of large-area perovskite solar cells by a blade coating process. The first part is to optimize the precursor solution and improve the thin-film uniformity. The composition of the precursor solution is the key to affect the uniformity and quality of the perovskite thin film. Analyzed the effects of different amounts of Tween60 (C64H126O26) and dimethylhydrazine ((CH3)2SO) on methylammonium lead halide (MAPbI3, MA=CH3NH3) thin films. The solution was doped with 330 ppm Tween60 and 1 M DMSO, and the film showed 110 preferred orientation, large grain size, high uniformity, and the PCE achieved 10.3% at an effective area of 0.1 cm2. The second part is to optimize the blading process gap and particle size of titanium dioxide (TiO2) that improved the efficiency. The electrical hysteresis properties and the FF was improved by adjusting the gap during blade casting, the particle size of TiO2, the MAPbI3 thickness to achieve ~300 nm, and the filling on TiO2. . Finally, the PCE was improved from 10.3% to 14.8% by using 300 μm as the gap during blading process and an 30-nm-thick TiO2. The third part discusses the process of large-area perovskite solar cells. The resistance was markedly increased by increasing the effective area, because the distance between the FTO electrodes is very large that increases the transmission distance of carriers. The resistance of the FTO was reduced by evaporating gold wires so that the carrier can be effectively transmitted to the receiving electrode. The PCE achieved 11.9% by increasing the active area from 0.1cm2 to 2.4 cm2 .
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Chang, Hao Wen, and 張浩文. "Highly efficient organic light-emitting diodes by blade coating process." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/45749698809586084998.
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博士國立清華大學
電子工程研究所
104
Solution-processable blade coating is applied to multi-layer phosphorescent organic light-emitting diodes (OLEDs) with five small-molecule hosts for the emission layer, including bis[3,5-di (9H-carbazol-9-yl)phenyl]diphenylsilane (SimCP2), 2,6-bis(3-(9H-carbazol-9-yl)phenyl) pyridine (26DCzPPy), 4,4’,4”-tris -(N-carbazolyl)-triphenylamine (TCTA), 9,9-bis[4-(3,6-di-tert-butylcarbazol-9-yl) phenyl]fluorine (TBCPF), and 2,7-bis(diphenylphosphoryl)-9,9’-spirobi[fluorene] (SPPO13). In general, blade coating gives low surface roughness of around 0.2 nm without phase separation of the emitter and the host. 1,3-Bis[2-(4-tert-butylphenyl)- 1,3,4-oxadiazo-5-yl]benzene (OXD-7) is added to tune the electron transport. Among all the hosts, 26DCzPPy and SimCP2 have by far the best electron–hole balance and consequently they show the highest efficiency. For SimCP2, the maximal efficiency is 15.8 cd/A for blue emission and 24.2 cd/A for white emission. The efficiencies for the hosts is found to be quite different from the efficiencies in vacuum evaporation for the same device structures. Large-area top-emitting OLEDs (TEOLEDs) with multi-layer structure are successfully demonstrated using blade coating on ITO-free substrate. The semitransparent cathode of TEOLED is composed of lithium fluoride (LiF), aluminum (Al) and silver (Ag). The composition of 3 nm Al and 10 nm Ag has a transmittance of 56% and a sheet resistance of 11 Ω/□. It is applied to the green phosphorescence device with an emissive area of 2 cm by 2.5 cm. The maximum current efficiency is 25.2 cd/A with high light-emission uniformity within 10% variation. The large-area TEOLEDs show comparable current efficiency as the small-area devices with an emissive area of 2 mm by 2 mm (having the same device structure) and better efficiency than traditional large-area bottom-emitting devices. Cesium fluoride (CsF) and n-doped electron transport layer are applied to improve electron injection. At 6 V, the luminance is raised from 141 cd/m2 to 502 cd/m2 and 304 cd/m2, respectively. Tandem WOLED is initially fabricated by blade coating process. The crystallization in bottom EL unit is reduced by coating low solubility material on the connecting layer. PEDOT:PSS has low solubility, so it efficiently protects bottom structure from crystallization. TAZ replaces TPBi which easily crystallizes in high temperature as ETL, thus the crystallization is solved. However, the bottom EL unit is dissolved during spin-coating PEDOT:PSS, so the luminance of bottom EL unit is weak. Blade-coated PEDOT:PSS shows reduced dissolution because of the advantage of rapid drying. Finally, the current efficiency is 5.8 cd/A; the CIE coordinates is (0.36,0.41); the color temperature is 4735 K.
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Chiu, Yu-Chian, and 邱鈺茜. "Unmodified small-molecule organic light-emitting diodes by blade coating." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/64749793511938515710.
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碩士國立交通大學
電子物理系所
100
Blade coating with substrate heating and hot wind is demonstrated to be a general platform for multi-layer deposition of unmodified small-molecule organic semiconductors. Most unmodified small molecules, originally designed for vacuum evaporation, can be blade coated while the solubility is above 0.5%. High uniformity is achieved for scale over 5 cm. Green devices by blade coating are 2,6-bis(3-(carbazol-9-yl)phenyl)pyridine (26DCzPPy) as the host, tris[2-(p-tolyl)pyridine]iridium(III) (Ir(mppy)3) as the emitter. When 4,4',4"-tris-(N-carbazolyl)-triphenylamine (TCTA) and 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) is used as the hole transporting layers, the efficiencies are 38.3 cd/A, 13.8 lm/W and 41.9 cd/A, 23.4 lm/W, respectively. The optimized organic light-emitting diodes (OLED) structure developed for vacuum deposition can therefore be exactly copied by the low cost blade coating method in solution.
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Chang, Yu-Han, and 張玉函. "Blade coating for polymer solar cells and multilayer polymer photo-detectors." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/22429768905756481740.
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碩士國立交通大學
物理研究所
97
A donor-acceptor blend for bulk hetero-junction polymer solar cells and polymer photo-detectors are studied by using poly(3-hexylthiophene) (P3HT) as the donor and (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) as the acceptor. Desired ordered donor-acceptor self-organization is achieved by blade coating with high carrier mobility. The polymer solar cell with power conversion efficiency (PCE) is 3.8% in this study, which is 46% higher than that obtained by spin coating in toluene solution (2.6%). In addition, the multilayer photo-detector can be achieved by blade coating to reduce dark current density to 10-5 mA/cm2. That is about 100 times lower than that of single layer structure by spin coating, enhancing the sensitivity.
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Chang, Bo-Jie, and 張博捷. "Organic light-emitting diodes and solar cells by blade coating method." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/26818321483371975470.
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碩士國立清華大學
電子工程研究所
99
The blade coating method has been overcame the dissolution and accomplished the multi-layer structure. In this thesis, organic light-emitting diodes (OLEDs) and organic solar cell are made by blade coating method. For OLEDs, various fluorescent emitters are introduced into the Blue S host to produce various colors including white. The current efficiency of 4.3 cd/A is achieved for blue, 9 cd/A for orange, and 6.9 cd/A for white. Bulk heterojunction organic solar cell with poly(3-hexylthiophene) (P3HT) donor and (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) acceptor is deposited by blade coating method. The fabrication throughput is greatly enhanced. The blade coated film has a smoother surface roughness of 3.5 nm compared with 10.5 nm for solvent annealing, yet the desired phase separation in the 50 nm scale forms despite of the rapid drying. Single layer solar cell shows power conversion effi-ciency of 4.1 % with blade coating in chlorobenzene, same as solvent annealing de-vice. Multi-layer device with carrier blocking layers fabricated entirely of the less toxic toluene also gives efficiency of 4.1 %. Keywords: organic light-emitting diodes、organic solar cells、blade coating method、 multi-layer、bulk heterojunction solar cells、phase separation、blocking layer
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Lin, Yu-Sung, and 林育頌. "Large area uniform layer of organic material by blade coating method." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/59458728049195895037.
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碩士國立交通大學
物理研究所
101
The thesis develop solution-processed large-area organic light-emitting diodes(OLEDs) by blade-only coating method. Large-area uniform films and mutual dissolution between different organic layers are controlled. The advantages of blade-only method are low cost, easily fabricating large-area devices, and compatible with roll-to-roll process for high throughput. Replace the original method by mechanized way can analysis the parameters of film thickness and uniformity more objectively, reducing the instability by human factors, and can maintain the desired organic film thickness and uniformity in a larger range of coating. Reducing the costs of the method, and let the blade-only coating method to fabricate an organic light-emitting diodes have more development of commerce.
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林建安. "Study on lifetime of organic light-emitting diodes by blade coating." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/szuu3e.
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碩士國立交通大學
影像與生醫光電研究所
102
There are two factors affecting the lifetime of OLED, divided into intrinsic and extrinsic types. The largest source of extrinsic factor is the moisture and oxygen of environment. Since highly active metal cathode and the organic materials in OLED are quite sensitive to moisture and oxygen, these parts will be eroded easily. When the current through the OLED, the parts which were eroded will not light and showing black spots. As time becomes longer, the black spots become larger and light parts become smaller,it makes OLED's brightness decline. In this thesis, we use improved encapsulation conditions to inhibit the growth sources of black spots in OLED, such as new glue、sandblasting glass、getter and encapsulation device. However, we still find that the brightness of OLED declines with time. The reason for this phenomenon is caused by the organic materials or the device structure, and these are the intrinsic factors. In this thesis, we use green PHOLEDs (ITO/PEDOT:PSS/TcTa/26DCzPPy:Ir(mppy)3=94:6/TPBi) as the standard, and using some methods, such as change HTL、Host material，add PFI(perfluorinated ionomer) to change HIL work function, EML use mixed host system. We observed the brightness changes under the constant current and setting the starting point of brightness as 1000 nits, and finally, we found that the mixed host system can improve the lifetime of the devices effectively.
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Lai, Chia-Hsin, and 賴佳忻. "The Influence of Coating Temperature and Solvent Ratio on Active Layer by Blade-Coating for Perovskite Solar Cells." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/9ev5ye.
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碩士國立中央大學
化學工程與材料工程學系
106
In recent year, perovskite solar cells has developed widely and quickly. In order to commercialize, we use blade-coating method which is more easily to up-scale than the most commonly used spin-coating process to investigate the effect of the precursor solvent, coating temperature, and the ratio of the mixed solvent. We find that there is obvious difference in film thickness and continuity when used distinct single or mixed solvent. The bad absorption of the active layer attributed to the discontinuous film or when the film is too thin, which caused the low device short circuit current. Coating temperature is the key of the roughness of the film. The solvent will keep flowing because of the surface tension after the blade go through when in lower coating temperature, which lead to the uneven morphology. In contrast, when it comes to higher coating temperature, the solvent volatilize so quick that bring about the holes on the film surface, result the lower coverage. Coating temperature is also the main role of the phase change when forming the perovskite crystalline. The precursor react directly into the ordered perovskite crystal at higher coating temperature, the unstable solvate and intermediate are found less. Furthermore, we discuss the film quality of the different solvent ratio of GBL and DMSO. The more DMSO, the larger the crystalline, and also get the better power conversion efficiency when applied to the solar cells. On the contrary, the more GBL, the bigger the density of the nucleus, cause the limited grain size. Due to the characteristic of the solvent GBL, the film is easily form the ring-like surface when the solvent volatilize and emerge the center-to-outer heat convection, which is the reason why the roughness and defects. This study is the analyzation about the above three optimization and got the best coating temperature 130℃ and the best ratio of the solvent GBL: DMSO=1:9(v: v), the n-i-p and p-i-n type solar cells respectively yield 12.16% and 13.19%. After enlarge the active area about 120 times as p-i-n type module with the efficiency of 11.13%. The advantages such as easy-made, material used effectively, and no active area limitation, blade-coating is a very promising process for up-scale manufacture.
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Lin, Man-Chun, and 林曼鈞. "216 cm2 active area highly efficient organic solar cell by blade coating." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/3yp9wr.
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碩士國立清華大學
電子工程研究所
105
Recently, the anomalies of the global climate is gradually intensifying. In order to sustain the environment we lived, we must reduce the amount of carbon dioxide emissions and find the way to develop the sustainable energy. The green energy has been being developed from the past years by many outstanding teams from the world. However, in all of the green energy, the solar cell is the most environmentally-friendly one. Taiwan is located in the subtropical region so there is sufficient intensity of sunshine which is lasting average one third of a day. Thus, it is conductive to develop this kind of the new alternative energy in Taiwan. Lately, the solar cells are most of inorganic solar cells, but it has disadvantage of costliness and pollution. In contrast, organic solar cells have more commercial value than inorganic solar cells because of its advantage which are simple process, manufacturing cheaper and more environmentally-friendly. In the near future, it is necessary for organic solar cell to enlarge to reduce manufacturing cost and be more practical in our life. Moreover, the organic solar cells with flexible substrate or translucent electrodes can be more compatible for buildings or other constructions. The combination with constructions and organic solar cells will be more various and aesthetic.This thesis is mainly about the development of organic solar cell process fabricated on 20 cm x 30 cm glass substrate with active area of 216 cm2. At first, we used the structure ITO/ PEDOT:PSS/ P3HT:PC61BM/ LiF/ Al for our reaserch and reached power conversion efficiency (PCE) of 1.62%. And the structure ITO/ PEDOT:PSS/ PBDTTT-EFT: PC71BM / LiF / Al also achieved power conversion efficiency (PCE) of 5.2 %[A4]. Importantly, the large-area device based on P3HT: PC61BM and PBDTTT-EFT: PC71BM blend can retain upon 60% and 90%, respectively.At last, the metal electrode was changed to a translucent structure ITO / PEDOT: PSS / PBDTTT-EFT: PC71BM / LiF / Al / Ag. The device achieved 3.59% power conversion efficiency[A4]. Key word : Blade-coating、Large-area、Organic solar cells、High efficiency、Polymer、Thin-film process、P3HT、PBDTTT-EFT、PC61BM、PC71BM
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Wu, Min-Fang, and 吳旻芳. "Self-assembled macroporous photonic crystal-based insecticide detectors by doctor blade coating." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/rz35f5.
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碩士國立中興大學
化學工程學系所
107
Because there are pests in Taiwan all of the four seasons, the only effective method to prevent those situations is cut off the route of disease transmission. Thus, in the critical situation, the most effective manner of killing pests is using the insecticides. The main components in traditional insecticides are Pyrethrins and Pyrethroids. The vapor of the toxic compound in insecticides would let the human’s health and the environment be injured. Hence, the demands on detecting the harms provoked by toxic compounds become more and more so that the objects including environmental monitoring and health risk assessment, etc. could be facilitated. The macroporous polymer films with three-dimensional hexagonal closest packing which consists of the ethoxylated trimethylol-propane triacrylate (ETPTA) with uniform pore size where the 2-hydroxyethyl methacrylate (HEMA) were coated on are continuously prepared by a simple, roll-to-roll compatible doctor blade coating technology and utilized as the detectors of the vapor of insecticides. According to the results, it is observed that the diffracted wavelength by this composite film would change with the insecticide pressure in a short time. Besides, the offsets of the diffracted wavelength could also be adjusted by the pore size of the macroporous films. Based on the apparent changes in color, the content of insecticides around surroundings could be quickly identified by the human’s eye. As reported by the advantageous like the lower energy consumption, lower cost and more environmentally friendly, it is proved that this film could satisfy the demands of human society.
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Cai, Chang-Yun, and 蔡昌運. "Superhydrophobic anti-ultraviolet and anti-near-infrared films by doctor blade coating." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/25322848102909359883.
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碩士國立中興大學
化學工程學系所
103
This research reports a scalable and roll-to-roll doctor blade coating technology for fabricating polymer films with anti-ultraviolet, anti-near-infrared, and self-cleaning properties. This technology is utilized to prepare double-layer 200 nm silica colloidal crystal-polymer composites and 500 nm silica colloidal crystal-polymer composites. The silica microspheres in these composites can then be selectively removed to present flexible self-standing macroporous polymer films with crystalline arrays of 200 nm air cavities and 500 nm air cavities. Both optical measurements and theoretical predications reveal that the as-prepared transparent double-layer macroporous films exhibit anti-ultraviolet and anti-near-infrared properties by the three-dimensional ordered air cavities based on the Bragg''s diffractive theory. The void size of pores is controlled by tuning the duration of reactive ion etching process prior to the removal of silica microspheres. Superhydrophobic surface can be achieved by surface modification with 1H, 1H, 2H, 2H- Perfluorodecyl Acrylate. This research further that demonstrates the as-prepared transparent porous films are with self-cleaning property.
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Ko, Ya-Lin, and 柯雅齡. "Self-assembled macroporous photonic crystal-based vapor detectors by doctor blade coating." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/72982260183799004434.
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碩士國立中興大學
化學工程學系所
103
This research reports a scalable and roll-to-roll doctor blade coating technology for self-assembling silica particles to fabricate flexible self-standing macroporous ethoxylated trimethylol-propane triacrylate (ETPTA) films with crystalline arrays of air cavities. The pores of macroporous films can be coated with 2-hydroxyethyl methacrylate (HEMA) to create HEMA/ETPTA composite macroporous films. The optical measurements and theoretical predications reveal the as-prepared macroporous films exhibit optical diffraction by the three-dimensional ordered air cavities based on the Bragg''s diffractive theory. Capillary condensation of a condensable vapor leads to the redshift of the optical stop bands, which demonstrates vapor detection is enabled by the as-prepared macroporous composite films. Besides, this research further reveals that the extent of redshift increases with the thickness of coated HEMA film and the pore size of the macroporous films.
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陳佳夢. "Development of technology toward large-area organic solar cells manufactured by blade-coating." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/20451434458645867724.
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碩士國立清華大學
電子工程研究所
100
Energy shortage has become one of the important issues to be resolved. People are eagerly looking for alternative energy sources to replace traditional fossil fuels. Organic solar cells have attracted much attention due to their unique properties such as low-cost, simple fabrication process and flexibility. In addition, it can be combined with roll-to-roll process to fabricate large-area organic solar cell. Most of the organic solar cells are fabricated using spin-coating technique; however, this technique is not applicable for large-area device fabrication. Therefore, we develop blade-coating process to fabricate large-area organic solar cells, not only enhancing the efficiency of material usage but also developing toward roll-to-roll process in the future. In this work, the hole transport layer and active layer are deposited by blade-coating method. The active layer was a bulk heterojunction (BHJ) consisting of P3HT and PCBM. However, the uniformity of large-area blade-coating will be affected by several factors such as the flow variability, surface tension of the solution and the velocity of blading. We discuss the different heating methods and use low boiling point CB to replace DCB as the solvent of active layer. To develop the serial connection of large-area devices, the scaling effect of the fabricated devices is studied by varying the widths of active area while keeping lengths the same. As a result, with increasing the width of active area, the impact of series resistance is more significant but the aperture ratio is increased. Therefore, an optimal width of the active area could be obtained, showing a good agreement with the simulated results of organic large-area solar cell. Therefore, we expect the series of large-area solar cells could be a good reference for the future.
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Li, Cheng-Xian, and 李承憲. "High Performance and Stability in Ternary Organic Solar Cells Fabricated by Blade Coating." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/a2avg6.
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Liu, Chang-Yao, and 劉昌曜. "The key process for large-area blade-coating polymer/organic light emitting diode." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/73689094651761991490.
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Chiu, Yung-Hsiang, and 邱詠翔. "Blade coating method for vertical space-charge-limited transistor using high carrier mobility polymer." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/30574778599938061029.
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碩士國立交通大學
物理研究所
99
Comparing to high cost and complicated fabrication process of small molecule organic semiconductor devices, conjugated polymer have been widely explored because of its advantages such as soluble process and its flexibility. Although spin coating is the most common technique for casting polymer films in solution process, its material usage is low. In this work, we use the blade coating method which has been demonstrated to have a high material usage. We demonstrate that even the solubility of a polymer is low, by using the blade coating method, the polymer film can still be fabricated easily. Poly(2,5-bis(3-alkylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT-C14) is a kind of liquid crystal molecule. By annealing at high temperature and transient cooling, its liquid crystal phase and high carrier mobility can be obtained. PBTTT diode shows higher current density compared to poly(3-hexylthiophene -2,5-diyl) (P3HT) diode. Finally, we demonstrated the influence of different concentration tetrafluoro -tetracyanoquinodimethane (F4TCNQ) doping on the poly(9,9-di-noctylfluorene-alt -(1,4-phenylene-((4-sec-butylphenly)-imino-) -1,4-phenylene) (TFB) diode.
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Lo, Fang-Tsai, and 羅芳財. "High efficiency blue phosphorescent small molecule organic light-emitting diodes by blade coating method." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/25176644057737685587.
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碩士國立交通大學
物理研究所
101
In this thesis, highly performance blue phosphorescent small-molecule organic light-emitting diodes are fabricated by blade coating. In order to optimize the efficiency and to decrease the driving voltage of the blue phosphorescent devices, the film thickness, the transporting materials and the structure of devices are tuned while emissive layer host of 6-bis(3-(9H-carbazol-9-yl)phenyl)pyridine (26DCzPPy) and triplet emitter of bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyr-idyl)iridium(III) (FIrPic). For FIrPic: 26DCzPPy as emissive layer, the current efficiency of 24 Cd/A, power efficiency of 9.44 lm/W, and luminance of 583.2 Cd/m2 is achieved at 8 V. Besides for FIrPic: SimCP2 as emissive layer, current efficiency of 13.1 Cd/A and luminance of 673 Cd/m2 is reached at 9 V. The driving voltage can be decreased by using SimCP2 as host material of emissive layer.
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Shih, Yi-Lun, and 施羿綸. "Improve the dissolution problem of high efficiency small molecule OLED by blade coating method." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/15613114829867622225.
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碩士國立交通大學
物理研究所
101
The blade coating cause the high efficiency small molecule OLED dissolving the interface between organic layers, this thesis discuss how to observe this situation and the use blade coating process improvement and evaporation process of the component to compare to each other. The first layer ( HTL ) of material is N, N'-bis (naphthalen-1-yl)-N, N'-bis (phenyl)-benzidine ( NPB ), then etching clean boundary by reactive ion etching, and depositing emitting layer by blade coating. Changing the thickness of the HTL, heating conditions, blower conditions, and selection of solvent, and finally to fluorescence microscopy observed changes in boundary conditions and found that when the thickness of the thinner HTL back the boundaries of its more obvious case, the boundary back order of degree: 15 nm> 20 nm> 30 nm> 35 nm, when there is external blower and heating conditions of the situation is better than no blower and no heating conditions, boundary degree back in order: no blower and no heating> blower and heating, the choice of solvent, the boundary back order of degree: chlorobenzene > chloroform > methanol > toluene, methanol without solute ; Select CB as the solvent of EML, the following structure: ITO / PEDOT / NPB / PO-01-TB: CBP / TPBi / LiF / Al, the efficiency of the EML to 20 nm: 20.5 lm / W, 33.82 cd / A, EML to 30 nm up to: 19.74 lm / W, 41.32 cd / A.
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Tseng, Yong-Jhe, and 曾永? "Effects of thin film metallic glass coating on skin grafting using a dermatome blade." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/75506806799669046613.
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碩士國立臺灣科技大學
材料科學與工程系
103
Skin grafting is usually used to treat extensive wounding, scald, severe skin loss area and specific surgeries, which require for skin healing. A dermatome blade is typically used for skin grafting and then to obtain a good quality of dermatome blade is necessary. Based on previous research in our group, the wound surface roughness is found to be influenced by the sharpness and durability of dermatome blade. As a result, the sharper blade is expected to help reduce skin damages and accelerate the wound healing. Coating is one of promising approaches to enhance the sharpness and durability of dermatome blades. Thin film metallic glasses (TFMGs) would be a good candidate for enhancing the surgical performance of dermatome due to their excellent mechanical properties. In this study, 200nm-thick Zr-based, W-based and Fe-based TFMGs are deposited on dermatome blades by using magnetron sputtering. The wear resistance and sharpness of the dermatome blade are found to be enhanced after coating. It is suggested that the unique properties of TFMG such as high strength, good wear-resistances play roles in protecting dermatome blade during animal test. However, there is no obvious reduction of surface roughness examined on TFMG-coated dermatome blade. In addition, compared with the bare dermatome blade, wound healing and biopsy morphology, performed by the TFMG-coated one, exhibit no apparent improvements. This result might be attributed to the inhomogeneous nature of animal as well as the healthy condition of animal.
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Hou, Min Yao, and 侯閔耀. "Blade Coating 2D/3D Perovskite Films for High Efficiency and Stable Preovskite Solar Cells." Thesis, 2019. http://ndltd.ncl.edu.tw/cgi-bin/gs32/gsweb.cgi/login?o=dnclcdr&s=id=%22107CGU05063024%22.&searchmode=basic.
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Tsai, Yueh-Lin, and 蔡岳霖. "Characteristics of TIPS-pentacene based organic thin film transistors fabricated by blade coating method." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/33242098976223279839.
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碩士國立清華大學
材料科學工程學系
102
In this thesis, we fabricated flexible OTFT devices with soluble gelatin as gate dielectric and soluble p-type TIPS-pentacene as the semiconductor layer by using solution process. We found that the parameters of blade coating would affect the characteristics of OTFT devices significantly. The best characteristics of OTFT device occur when the TIPS-pentacene thin film is coated along the charge transport channel with a coating speed of 1 mm/sec at a substrate temperature of 70 ℃. Its field effect mobility is up to 1.71 cm2V-1s-1. Based on AFM and XRD, the crystal of TIPS-pentacene grows along the coating direction when the coating speed is 1 mm/sec and the substrate temperature is 70 ℃. The thin film morphology consisted of many plate-like domains with long-range ordering and the crystallinity increases a lot at the same coating speed and substrate temperature. The formation of plate-like domains and the increment of crystallinity are responsible for better OTFT devices characteristics. We have also demonstrated that the anisotropy of the electrical characteristics of the OTFT devices is in match with oriented TIPS-pentacene crystal growth direction. The influence of coating direction on field effect mobilities is also illustrated.