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Chemical Interactions between tool and Aluminium alloys in metal cuttingErkers, Louise January 2020 (has links)
Aluminium applications in automotive will increase by 25 % over the next decade, mainly driven by the electrification and the reduction of fuel consumption. This diploma work aims to increase the understanding of the chemical interactions between aluminium alloys and typical tool systems in metal cutting. First the temperature at the tool-chip interface was estimated by FEM simulations, using the software AdvantEdge. Thereafter the chemical interaction of the tool-chip interface was calculated at the simulated temperature using the Thermo-Calc software. The thermodynamic data and descriptions of the multicomponent systems used where found in the literature, assessed by other authors, but critically reviewed for the use in this work. The results of the FEM simulations indicate that the temperature for machining aluminium with PCD and cemented carbide is between 60-80 % of the melting temperature of Al7wt %Si alloy. The calculations of the chemical interaction in turn results in that several hard precipitates can stick to or transform on the surface of the workpiece or tool-chip interface, for example SiC, Al4C3 and evidently diamond from the tool. This work concluded that more predictive modelling is needed to refine the results and the results from this work needs to be confirmed with experiments. The results show that the modelling can predict the reaction phases at the tool-chip interface, this can be used as input for the tool wear mechanisms during development of tooling solutions. / Aluminium användningen inom fordonsindustrin förväntas öka med 25 % under det närmsta decenniet, främst på grund av elektrifiering men också för att för att minska bränsleförbrukning. Målet med detta examensarbete är till att öka förståelsen för de kemiska interaktionerna mellan aluminiumlegeringar och typiska verktygssystem vid metallskärning, framförallt vid bearbetning av aluminiumlegeringar innehållande kisel med ett TiN-belagt PCD-verktyg och icke-belagda verktyg. Detta gjordes genom prediktiva FEM-simuleringar av temperatur, med hjälp av mjukvaran AdvantEdge. Parallellt med detta skapades databaser för simulering av den kemiska interaktionen mellan skär och bearbetningsmaterial i programvaran Thermo-Calc. De termodynamiska data och beskrivningarna av de termodynamiska system som används var bedömda av andra författare men kritiskt granskade för användning i detta arbete. Resultaten av FEM-simuleringarna gav den beräknade temperaturen för bearbetning av aluminium med PCD ligger någonstans mellan 60-80 % av smälttemperaturen för Al7wt % Si-legering. Beräkningarna av den kemiska interaktionen resulterar i sin tur i att flera hårda utskiljningar kan fastna på eller transformera på ytan mellan arbetsstycket och verktyget, till exempel SiC, Al4C3och diamant från verktyget. Resultaten från detta arbete visar att det går att förutsäga fasomvandlingar mellan skär och arbetsstycket, samt att detta kan användas som indata för skärförslitning under utvecklingen av verktygslösningar.
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Die Aluminiumbatterie: Herausforderungen für die industrielle Fertigung - ProBaSol: Teilprojekt: Umsetzung vorlaufend entwickelter Feststoffbatteriekonzepte auf Basis des hochvalenten Kations Aluminium: SchlussberichtStöcker, Hartmut, Meyer, Dirk C. 10 July 2024 (has links)
Das Vorhaben verfolgt das Ziel der Implementierung einer neuartigen Technologie zur Fertigung elektrochemischer Energiespeicher als Alternative zu Li-basierten Batteriesystemen (LIB). Dabei soll es von den Ergebnissen eigener abgeschlossener bzw. aktuell laufender Verbundvorhaben profitieren und den systematischen Aufbau einschlägiger Kompetenzen im Sinne eines Transfers vervollständigen. Schwerpunktmäßig wird auf eine Festkörperbatterie für mobile hochvalente Ionen sowie die dazugehörige Fertigungstechnologie für Festkörperelektrolyte (FKE) und Elektroden, insbesondere mittels Kurzzeittempern mit Blitzlampen (engl. Flash Lamp Annealing – FLA) sowie Anodischem Oxidieren (AO) gesetzt. Wesentliche Vorteile sind die erzielbaren Energiedichten, die hohe Sicherheit, die umfassende Verfügbarkeit der Materialien sowie die Recyclierbarkeit der Systeme. Im Ergebnis soll neben einer detaillierten Komponente-Eigenschaft-Matrix (KEM) sowie Zellstudien, ein Prototyp in Einsatzumgebung als Voraussetzung für die industrielle Fertigung vorliegen. Die volumetrische Energiedichte kann potentiell doppelt bis viermal so hohe Werte im Vergleich zu kommerziellen LIB erreichen. Zudem ist ein Kostensenkungspotential von bis zu 20 % bezogen auf den Preis pro kWh gegeben. Das Erreichen der Ziele soll durch begleitendes Technologiemanagement und Systemanalyse unterstützt werden.
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Développement d'une méthodologie de conversion de pièces structurelles de l'acier vers l'aluminiumPépin, Jean-François January 2009 (has links)
Au cours des dernières décennies, l'utilisation de l'aluminium n'a cessé d'augmenter dans différents secteurs industriels. Par ailleurs, dans le domaine de la Conception Assistée par Ordinateur (C.A.O.), les opportunités de développement d'outils de design de l'aluminium sont encore nombreuses. Le présent mémoire propose une méthodologie générale permettant la conversion de pièces structurelles de l'acier vers l'aluminium. Une démarche définie par cinq étapes principales est élaborée à l'aide de différents algorithmes : (1) Analyse mécanique d'une pièce structurelle en acier ; (2) Définition des critères de conception ; (3) Paramétrage de la pièce ; (4) Analyses itératives de pièces d'aluminium ; (5) Élaboration des alternatives retenues et rejetées du design en aluminium. Parallèlement au développement de la méthodologie, les possibilités d'implémentation sont étudiées. Certains concepts d'automatisation sont proposés à l'aide du logiciel CATIA. Un exemple général est proposé, à la fin du mémoire, afin d'illustrer les différentes étapes de la méthodologie.
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Étude des mécanismes de formation et du comportement des dépôts au pourtour de cellules d’électrolyse d’aluminiumAllard, François January 2014 (has links)
Le Canada est un joueur majeur dans l’industrie de l’aluminium. Pour demeurer compétitif mondialement, le coût de production de l’aluminium doit constamment être réduit. Les cellules d’électrolyse requièrent une grande quantité d’énergie (~13 kWh/kg) pour produire l’aluminium. De plus, l’efficacité du procédé Hall-Héroult est diminuée par la présence de dépôts à l’interface entre l’aluminium et le bloc cathodique. Ces dépôts causent une restriction pour le passage du courant engendrant une augmentation de la perte de potentiel. Les dépôts à la surface du bloc cathodique se divisent en différentes catégories. Il y a le pied de talus qui est situé sous le talus et sur le bloc cathodique. La partie du pied de talus près de la paroi de la cellule d’électrolyse possède une composition chimique similaire au talus. La partie à l’extrémité du pied de talus possède un ratio de cryolite plus élevé que le talus et elle est davantage sursaturée en alumine. L’extrémité du pied de talus peut atteindre jusqu’à 85 % d’Al[indice inférieur 2]O[indice inférieur 3]. Le pied de talus se forme par les pertes de chaleur situées au niveau de la paroi et au fond de la cellule. Il prend de l’expansion lorsque la température locale est inférieure à la température de solidification de la phase Na[indice inférieur 3]AlF[indice inférieur 6] (944 °C à un ratio de cryolite de 2,5). Le ratio de cryolite de l’extrémité du pied de talus augmente puisqu’il y a migration des cations Na[indice supérieur +] vers la cathode. La boue est composée d’un mélange d’Al[indice inférieur 2]O[indice inférieur 3] solide en suspension dans le bain électrolytique liquide. Elle est située, en général, au centre de la cellule d’électrolyse et sur le bloc cathodique. De plus, un film de bain sursaturé en alumine peut se retrouver entre le pied de talus et la boue au centre. Le ratio de cryolite de la boue se situe entre 2,2 et 2,5 et la concentration d’Al[indice inférieur 2]O[indice inférieur 3] varie entre 20 % et 50 %. La température de solidification de la phase Na[indice inférieur 3]AlF[indice inférieur 6] est fortement influencée par l’excès d’AlF[indice inférieur 3] et par la concentration en CaF[indice inférieur 2]. De plus, il y a présence d’une fraction liquide dans les dépôts dès 730 °C compte tenu de la présence de Na[indice inférieur 5]Al[indice inférieur 3]F[indice inférieur 14], Na[indice inférieur 2]Ca[indice inférieur 3]Al[indice inférieur 2]F[indice inférieur 14] et NaCaAlF[indice inférieur 6]. La fraction liquide augmente lorsque le ratio de cryolite diminue. Il y a évaporation de bain acide à partir d’environ 730 °C. Les dépôts dans la cellule d’électrolyse sont donc à l’état solide-liquide dès que la température atteint environ 730 °C.
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Rheocasting of Aluminium Alloys : Slurry Formation, Microstructure, and PropertiesPayandeh, Mostafa January 2015 (has links)
Innovative materials with novel properties are in great demand for use in the criticalcomponents of emerging technologies, which promise to be more cost-effective and energyefficient.A controversial issue with regard to manufacturing complex industrial products isto develop advanced materials with optimised manufacturability in addition to the requiredmechanical and physical properties. The objective of this research study was to develop andoffer new solutions in material-processing-related issues in the field of mechanical andelectrical engineering. This was achieved by investigating the new opportunities affordedby a recently developed rheocasting method, RheoMetalTM process, with the goal of comingto an understanding of the critical factors for effective manufacturing process. A study of the evolution of microstructure at different stages of the rheocasting process,demonstrated the influence of multistage solidification on the microstructural characteristicsof the rheocast components. The microstructural investigation onquench slurry showed itconsists of the solute-lean coarse globular α-Al particles with uniform distribution ofalloying elements, suspended in the solute-rich liquid matrix. Such inhomogeneous slurryin the sleeve seems to play a critical role in the inhomogeneity of final microstructure. Inthe rheocast component, the separation of the liquid and solid parts of slurry during fillinginfluenced on the microstructural inhomogeneity. The relationship between the microstructural characteristics and properties of the rheocastcomponents was investigated. The study on the fracture surfaces of the tensile-testedspecimens showed that the mechanical properties strongly affected by microstructuralinhomogeneity, in particular macrosegregation in the form of near surface liquid segregationbands and subsurface porosity. The thermal conductivity measurement showed variation ofthis property throughout the rheocast component due to variations in the ratio of solute-leanglobular α-Al particles and fine solute α-Al particles. The result showed silicon in solidsolution have a strong influence (negative) on thermal conductivity and precipitation ofsilicon by heat treatment process increase the thermal conductivity. / RheoCom
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Development of novel composite cement systems for the encapsulation of aluminium from nuclear wastesMcCague, Colum January 2015 (has links)
Currently in the UK, composite blends of Portland cement (PC) and blastfurnace slag (up to 90%) are commonly used for the encapsulation of low and intermediate level wastes. The high volume replacement of PC is considered necessary in order to to reduce the high heat generation resulting from cement hydration in 500 litre waste packages. While suited to the majority of waste streams, the high pH environment in such systems (usually around 12.5 -13), will cause the corrosion of certain waste metals such as aluminium. Since aluminium is only passive between pH4 - 8.5, the use of an alternative low-pH cement system could serve to reduce/inhibit the corrosion. However, before such cements can be considered, two main research problems must be addressed, as follows: (1) quantitative evaluation of alternative cement systems based on their corrosion performance with aluminium; (2) high heat generation due to the rapid rate of hydration. The research in this thesis was thus divided into two strands, as follows: (1) The design and development of a novel, scientifically robust testing facility for the quantitative monitoring of aluminium corrosion in cement pastes; (2) the development of novel cement composites based on weakly alkaline calcium sulfoaluminate (CSA) cement for the encapsulation of aluminium from nuclear wastes. The output from this research is considered to be of interest to the UK nuclear industry.
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On the effects of special boundary geometries on intergranular corrosion and grain boundary evolution in aluminiumHill, Lisa January 2013 (has links)
No description available.
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A contemporary approach to expressiveness in the design of digital musical instrumentsDalgleish, Mathew January 2013 (has links)
Digital musical instruments pose a number of unique challenges for designers and performers. These issues stem primarily from the lack of innate physical connection between the performance interface and means of sound generation, for the latter is usually dematerialised. Thus, this relationship must instead be explicitly determined by the designer, and can be essentially any desired. However, many design issues and constraints remain poorly understood, from the nature of control to the provision of performer-instrument feedback. This practice-based research contends that while the digital and acoustic domains are so different as to be fundamentally incompatible, useful antecedents for digital musical instruments can be found in the histories of electronic music. Specifically, it argues that the live electronics of David Tudor are of particular prescience. His home-made circuits offer an electronic music paradigm quite antithetical to both the familiar keyboard interface and the electronic music studios that grew up in the years after World War II, and are seen to embody a number of aspirational qualities. These include performer-instrument interaction more akin to steering rather than fine control, the potential for musical outcomes that are unknown and unknowable in advance, and distinct instrumental character. This leads to the central contribution of this research; the development of a Tudor-inspired conceptual framework that can inform how digital musical instruments are designed, played, and evaluated. To enable more detailed and nuanced discussion, the framework is broken down into a series of sub-themes. These include both design issues such as nuance, plasticity and emergence, and human issues such as experience, expressiveness, skill, learning, and mastery. The notion of sketching in hardware and software is also developed in relation to the rapid iteration of multiple designs. Informed by this framework, seven new digital musical instruments are presented. These instruments are tested from two different perspectives, with the personal experiences of the author supplemented with data from a series of smallscale user studies. Particular emphasis is placed on how the instruments are played, the music they can produce, and their capacity to convey the musical intentions of the performer (i.e. their expressiveness). After the evaluation of the instruments, the Tudorian framework is revisited to form the basis of the conclusions. A number of modifications to the original framework are proposed, from the addition of a dialogical model of performerinstrument interaction, to the situation of digital musical instruments within a wider musical ecology. The thesis then closes with a suggestion of possibilities for future research.
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Exploring Indian indigenous counselling techniques : evaluating their effectiveness and contribution to counselling psychologyMundra, Neha January 2013 (has links)
The purpose of this study was to explore whether Indian counsellors and psychotherapists in the UK practice in an indigenous way with their Indian clients. The aim was to find out more information about the different types of Indian indigenous interventions that may currently be used by these professionals. The study also bridges the gap in the literature about the lack of research on the practical uses and applications of Indian indigenous counselling skills in the UK.The study reports data from six face-to-face open-ended semi-structured interviews with Indian counsellors who have been trained in Western psychotherapeutic approaches and have knowledge of Indian psychotherapeutic approaches. The research was analysed using Interpretative Phenomenological Analysis (IPA). Firstly, the analysis concluded the use of several Indian indigenous interventions used by the participants, such as Prekshadhyan which can be used for psychosomatic pain relief, Jain virtue of forgiveness which can be useful for working with sexual abuse, use of spirituality and cultural beliefs for bereavement, and so on. Secondly, the analysis identified some of the most common barriers to therapy (e.g. stigmas and taboos) experienced by Indian clients in the UK, and it provided suggestions on how to overcome these. Finally, the analysis suggested factors that therapists should pay attention to (e.g. client context and use of Indian languages) in order to maximise Indian clients’ engagement in therapy and to minimise their exclusion from it.
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Verifiering av KedertakstolenFornander, Erik January 2010 (has links)
<p>The Kedertruss is the loadbearing part in the Keder weatherprotectionsystem and it has been analyzed concerning its loadbearing capacity. The Kedertruss is produced and manufactured by Wilhelm Layher GmbH & Co. KG and this report has been made for their Swedish division Layher AB. The Kedertruss, designed in Germany according to German designcode, has been recalculated concerning Swedish conditions according to Eurocodes and a ongoing European standardization project. The two-dimensional program Winstatik Frame Analysis has been used for evaluation of load effects. Capacity has been calculated by hand-calculations and it has been verified that the Kedertruss in its larger spans isn’t able to withstand the loads. The main problem is the greater snowloads which has been proofed to be the most unfavorable load for the Kedertruss. Apart from the commission from Layher AB a parametric controlled model of the Kedertruss has been made in Revit Structure</p>
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