Dissertations / Theses: 'Aluminium (Al)'

1

Nafisi, Shahrooz. "Effects of grain refining and modification on the microstructural evolution of semi-solid 356 alloy = Effets de l'affinage des grains et de la modification sur l'évolution microstructurale de l'alliage 356 semi-solide /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2006. http://theses.uqac.ca.

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Saoudi, Abdelhamid. "Prédiction de la rupture par fatigue dans les pièces automobiles en alliages aluminium /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2008. http://theses.uqac.ca.

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Thèse (D.Eng.) -- Université du Québec à Chicoutimi, 2008.
La p. de t. porte en outre: Doctorat en ingénierie, thèse pour l'obtention du titre de Philosophiae Doctor en ingénierie. CaQQUQ Comprend des réf. bibliogr. (f. 174-178). Publié aussi en version électronique. CaQQUQ

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3

Mohamed, Adel. "Effet des additifs sur la microstructure et les propriétés mécaniques des alliages d'aluminium-silicium /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2008. http://theses.uqac.ca.

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Thèse (D.Eng..) -- Université du Québec à Chicoutimi, 2008.
La p. de t. porte en outre: Thèse présenté[e] à l'Université du Québec à Chicoutimi comme exigence partielle du doctorat en ingénierie. CaQQUQ Comprend des réf. bibliogr. (f. [292]-314). Publié aussi en version électronique. CaQQUQ

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4

Blanchette, Hugues. "Développement d'un système de contrôle de qualité pour les lopins d'aluminium semi-solide[s] obtenus avec le procédé SEED /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2006. http://theses.uqac.ca.

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5

El, Sebaie Ossama. "L'effet de l'addition du "mischmetal", du taux de refroidissement et du traitement thermique sur la microstructure et la dureté des alliages Al-Si de type 319, 356, et 413 = Effect of mischmetal, cooling rate and heat treatment on the microstructure and hardness of 319, 3456, and 413 Al-Si alloys /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2006. http://theses.uqac.ca.

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6

Golbahar, Behnam. "Effect of grain refiner-modifier interaction on the performance of A356.2 alloy." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2008. http://theses.uqac.ca.

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Thèse (M.Eng.) -- Université du Québec à Chicoutimi, 2008.
La p. de t. porte en outre: Mémoire présenté à l'Université du Québec à Chicoutimi comme exigence partielle de la maîtrise en ingénierie. CaQQUQ Comprend des réf. bibliogr. (f. 149-155). Publié aussi en version électronique. CaQQUQ

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7

Yang, Deyu. "Rôle d'addition de magnésium sur l'occurence de la fonte naissante dans les alliages expérimentaux et commerciaux Al-Si-Cu et son influence sur la microstructure et les propriétés de traction de l'alliage = Role of magnesium addition on the occurence of incipient melting in experimental and commercial Al-Si-Cu alloys and its influence on the alloy microstructure and tensile properties /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2006. http://theses.uqac.ca.

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8

Wilson, G. R. "Surface studies of aluminium and aluminium alloys." Thesis, University of Newcastle Upon Tyne, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377646.

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9

Nadeau, Jean. "Identification d'un modèle linéaire pour l'analyse dynamique du procédé d'électrolyse de l'aluminium /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1993. http://theses.uqac.ca.

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10

Riverin, Gaston. "Purification de l'aluminium par cristallisation fractionnée /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1993. http://theses.uqac.ca.

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11

Ergin, Guvenc. "Étude de la mouillabilité des particules granulaires par les alliages d'aluminium durant la filtration d'aluminium /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2006. http://theses.uqac.ca.

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Thèse (D.Eng.) -- Université du Québec à Chicoutimi, 2006.
La p. de t. porte en outre: Thèse présentée à l'Université du Québec à Chicoutimi pour l'obtention du doctorat en ingénierie. CaQCU Bibliogr.: f. 130-147. Document électronique également accessible en format PDF. CaQCU

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12

Hellström, Hans-Olov. "Bone and aluminium /." Uppsala : Acta Universitatis Upsaliensis : Universitetsbiblioteket [distributör], 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8181.

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13

Gagné, Stéphane. "Effets de l'augmentation de la teneur en titane sur l'affinage des grains de l'alliage A356.2 /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2005. http://theses.uqac.ca.

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14

Khadir, Lahouari. "Étude du phénomène de résonance des pièces complexes en aluminium /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2007. http://theses.uqac.ca.

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Thèse (M.Eng.) -- Université du Québec à Chicoutimi, 2007.
La p. de t. porte en outre: Mémoire présenté à l'Université du Québec à Chicoutimi comme exigence partielle de la maîtrise en ingénierie. CaQQUQ Bibliogr.: f. 117-120. Document électronique également accessible en format PDF. CaQQUQ

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15

Burgmann, Flame Astra, and f. burgmann@usyd edu au. "Nanostructured Multilayer Coatings of Aluminium and Aluminium Oxide with Tungsten." RMIT University. Applied Sciences, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080424.135857.

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The development of nanostructured coatings which exhibit enhanced mechanical properties is currently of interest due to the importance of high performance coatings in a large range of applications. Single layer coatings have predominantly been used for these demanding applications, however the promising mechanical properties observed in multilayer coatings has shifted the focus of current research. In particular, there has been reports of the use of alternating materials with opposing mechanical properties, as seen in the abalone shell, which have exhibited hardness and toughness values significantly greater than either of their constituent materials. The main objective of this thesis was to fabricate Al/W nanostructured multilayers and determine if they exhibit enhanced mechanical properties. The Al/W nanostructured multilayers were fabricated using two different deposition techniques: pulsed magnetron sputtering and cathodic arc deposition. These two techniques differ in the energy of the depositing species and this results in significant differences in film properties. The indentation hardness of the coatings was measured using a Hysitron Nanoindenter. The relationship between the mechanical properties and microstructure was obtained using a range of characterisation techniques. Auger electron spectroscopy (AES), energy dispersive spectroscopy (EDS) and electron energy loss spectroscopy (EELS) were used to determine the chemical composition and stoichiometry, while cross-sectional transmission electron microscopy (XTEM) and energy filtered transmission electron microscopy (EFTEM) were used to explore the microstructure. The findings of this thesis showed very different results for the two deposition techniques. Although sputtering successfully produced well defined multilayers, no evidence of enhanced hardness was found for periods between 5 and 200 nm. On the other hand, arc deposited samples with intended periods between 1 and 200 nm showed a hardness enhancement above that of pure W, however the samples of highest hardness did not contain Al layers for much of their thickness. Arc deposited samples with the finest nominal periods (1 and 2 nm) contained W-Al intermetallics and were soft. The hardening mechanism was not attributed to a multilayer structure, rather to the introduction of defects in the W layers which acted as pinning sites for dislocations. A modified Hall-Petch equation for hardness enhancement fitted the data for W films prepared by pulsed cathodic arc in which the grain diameter was replaced by the nominal multilayer period. The difficulty producing Al layers on W surfaces in the cathodic arc was overcom e by changing the film growth mechanism by introducing Ar or O2 at the W/Al interface. In the latter case, Al2O3/W multilayers were formed but again showed no hardness enhancements. Complete microanalysis and characterisation of the multilayer structures is vital in determining the mechanisms which govern the hardness enhancements. The evidence in this thesis suggests that the defect density, and not the presence of interfaces are responsible for the hardness enhancement effect.

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16

Hellström, Hans-Olov. "Bone and Aluminium." Doctoral thesis, Uppsala University, Department of Surgical Sciences, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8181.

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Osteoporosis is a major health care problem, by reason of its devastating consequences, in particular hip fractures. Worldwide it has been estimated that the incidence of hip fracture will increase to more than 6 million per year by 2050 compared to 1.7 million per year in 1990. Osteoporosis can be caused by various factors namely, genetic, lifestyle and environmental factors, and since the rising incidence of its consequences is not fully explained by the growing age of the population, there is an urgent need to identify individual causal factors of this condition.

The present research has focused on aluminium, one potential environmental factor of importance for bone disease, and its possible relation to osteoporosis, since it is known to cause osteoporosis-like bone disease and has been associated with induction of progressive central nervous system diseases.

Aluminium is the third most common element in the earth’s crust and the most abundant metal (8%). It is widely utilized industrially and it is also naturally present in many foods. Although aluminium is ubiquitous in the human environment, evolution has not given it an essential biological function.

The aluminium content of bone was measured by inductively coupled mass spectrometry in a large group of patients suffering from hip fractures, high energy fractures and osteoarthrosis. An exponential increase in aluminium content of bone with age was found (p=0.0004). However, no significant association of aluminium in bone with occurrence of hip fracture or dementia could be found, and no indirect evidence was obtained, e.g. through bone mineral density or biomechanical properties, that aluminium is involved in the pathogenesis of osteoporosis. Although we accumulate aluminium in bone throughout our lives, and there are experimental suggestions that aluminium induces premature cell death, the body content of this metal does not seem to influence the overall mortality risk.

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17

Brooks, S. R. "Aluminium expansion processing /." Title page, contents and summary only, 1990. http://web4.library.adelaide.edu.au/theses/09ENS/09ensb873.pdf.

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18

O'Sullivan, Brendon. "Electroanalysis of aluminium." Thesis, University of Canterbury. Chemistry, 1997. http://hdl.handle.net/10092/6094.

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The aim of this project was the development of new analytical methods for the measurement of reactive (toxic) aluminium in natural waters (i.e. soil solutions, rivers and lakes). Indirect electrochemical methods were used. These involve the formation of a complex between a metal and a redox-active ligand. The coordination chemistry of two redox-active ligands and aluminium was studied using the techniques of solution thermodynamics. After complex formation with aluminium a shift in the ligand's redox potential is observed. Three ligands were studied voltammetrically. A theoretical model taken from the literature describing the shifts in ligand redox potential was shown to be inappropriate and the shifts were shown to result from the direct electrode reaction of aluminium-coordinated ligand. The effect of variation in complex stoichiometry was also studied. Shifts in ligand redox potentials may be exploited in the development of analytical applications. A flow injection analysis (FIA) system was constructed which allowed the amperometric measurement of aluminium after formation of a complex with the reagent 4-nitrocatechol. Incorporation of a micro-column of oxine-derivatised gel into the manifold eliminated the effect of interfering cations and allowed the selective measurement of reactive aluminium in natural waters. A problem was encountered with electrode fouling in the amperometric system. Two novel FIA strategies were developed to overcome this. Screen printing technology was used to fabricate chemically modified electrodes for the analysis of aluminium. General advantages of the application of this technology were revealed. The particular electrodes made here were suitable for 'in-field' measurement of reactive aluminium in natural samples. The oxine micro-column was used in conjunction with the screen printed electrodes allowing selective measurement of reactive aluminium. This gives flexibility in the linear working range and eliminates the effect of interfering cations.

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19

Norman, C. F. W. "Corrosion of aluminium." Thesis, University of Manchester, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374581.

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20

Tash, Mahmoud. "Effect [sic] des paramètres métallurgiques sur le comportement d'usinage des alliages 356 et 319 (étude de forage et de taraudage) /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2005. http://theses.uqac.ca.

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21

Xiao, Xiaoling, and S3060677@student rmit edu au. "Characterization of nano-structured coatings containing aluminium, aluminium-nitride and carbon." RMIT University. Applied Sciences, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20081217.100453.

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There is an every increasing need to develop more durable and higher performing coatings for use in a range of products including tools, devices and bio-implants. Nano-structured coatings either in the form of a nanocomposite or a multilayer is of considerable interest since they often exhibit outstanding properties. The objective of this thesis was to use advanced plasma synthesis methods to produce novel nano-structured coatings with enhanced properties. Coatings consisting of combinations of aluminum (Al), aluminum nitride (AlN) and amorphous carbon (a-C) were investigated. Cathodic vacuum arc deposition and unbalanced magnetron sputtering were used to prepare the coatings. By varying the deposition conditions such as substrate bias and temperature, coatings with a variety of microstructures were formed. A comprehensive range of analytical methods have been employed to investigate the stoichiometry and microstructure of the coatings. These include Transmission Electron Microscopy (TEM), Scanning Transmission Electron Microscopy (STEM), Electron Energy Loss Spectroscopy, Auger Electron Spectroscopy, X-ray diffraction and Raman spectroscopy. In addition to the investigation of microstructure, the physical properties of the coatings were measured. Residual stress has been recognized as an important property in the study of thin film coatings since it can greatly affect the quality of the coatings. For this reason, residual stress has been extensively studied here. Hardness measurements were performed using a nano indentation system, which is sensitive to the mechanical properties of thin films. This thesis undertook the most comprehensive investigation of the Al/AlN multilayer system. A major finding was the identification of the conditions under which layers or nanocomposite form in this system. A model was developed based on energetics and diffusion limited aggregation that is consistent with the experimental data. Multilayers of a-C and Al were also found to form nanocomposites. No hardness enhancement as a function of layer thickness or feature size was observed in either the Al/AlN or a-C/a-C systems. It was found that the most important factor which determines hardness is the intrinsic stress, with films of high compressive stress exhibiting the highest hardness. Nano-structured multilayers of alternating high and low density a-C were investigated. For a-C multilayers prepared using two levels of DC bias, evidence of ion beam induced damage was observed at the interfaces of both the low and high density layers. In addition, the structure of the high density (ta-C, known as tetrahedral amorphous carbon) layers was found to be largely unchanged by annealing. These results extend our understanding of how a-C form from energetic ion beams and confirms the thermal stability of ta-C in a multilayer. This thesis also presented the first attempt to synthesis a-C multilayered films with a continuously varying DC bias in sinusoidal pattern. The resulting films were shown to have a structurally graded interface between layers and verified that ion energy and stress are the most important factors which determine the structure of a-C films.

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22

Matthews, Stephen John. "Cavitation erosion of aluminium alloys, aluminium alloy/ceramic composites and ceramics." Thesis, Coventry University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317927.

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23

Impey, S. A. "The mechanism of dross formation on aluminium and aluminium magnesium alloys." Thesis, Cranfield University, 1989. http://dspace.lib.cranfield.ac.uk/handle/1826/3590.

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Metal loss is an unavoidable consequence of the large scale melting of aluminium and its alloys. The objective of such processing must be to minimise losses, both from an economic viewpoint and to ensure optimum quality of cast and wrought products. Aluminium losses during melting and casting are primarily due to the formation of dross, a mixture of oxide and melt. Many of the commercially important aluminium alloys contain appreciable levels of magnesium (up to 5%) which can result in enhanced oxidation rates that give rise to particular problems in recycling. Results are presented from a study aimed at reducing melt loss through a knowledge of the mechanism by which dross is formed. Work has centred on an understanding of the early stages in oxide scale growth, a study of growth kinetics and subsequent breakdown of these initial scales to form dross. In humid atmospheres, the amorphous oxide covering both aluminium and aluminium-magnesium at 750°C provides a highly effective barrier protecting the molten metal. In the absence of water vapour, oxide crystal development in aluminium-magnesium alloys is dominated by magnesium, and is extremely rapid in comparison with pure aluminium. Despite the different oxides formed, the manner of crystal formation at the 'amorphous' oxide-melt interface at 750°C on both aluminium and aluminium-magnesium is comparable. Nucleation and growth of crystals in the 'amorphous' film generates high stresses which result in failure of the surface oxide. Scanning electron microscopy has shown that the localised failure of this protective oxide film results in exudations forming on the melt surface, the size and number of which increase with exposure time. These exudations would appear to be the onset of dross formation. Parallel studies of the wetting characteristics of aluminium to alumina have shown that the reported non-wetting is due to the presence of the thin alumina film on the melt surface. Once broken, wetting of the alumina takes place and accounts for the exudation of molten metal through the surface oxide and hence dross formation.

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24

Boily, Pascal. "Application des capteurs thermiques implantés pour la détection du profil de gelée dans la cuve d'électrolyse /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2001. http://theses.uqac.ca.

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25

Ammar, Hany. "Effet des imperfections de la coulée sur les propriétés en fatigue des alliages de fonderie aluminium silicium = Effect of casting imperfections on the fatigue properties of aluminum-silicon casting alloys /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2006. http://theses.uqac.ca.

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26

Holmgren, Magnus. "Rening av väte vid återvinning av aluminium : Purification of hydrogen in aluminum recycling." Thesis, Linnéuniversitetet, Institutionen för maskinteknik (MT), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-26479.

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Detta examensarbete har utförts på Stena Aluminium (SA) i Älmhult. Undersökningen handlar om att mäta vätgashalten genom densitetsindexprover på smält aluminium, för att kartlägga hur vätgashalten påverkas av processtegen vid återvinning av aluminium i SAs produktions-anläggning. I arbetet ingick att undersöka vätgashalten för två olika legeringstyper (EN-AB 43400 och 46000), utvärdera avgasningseffektivitet för de utvalda legeringstyperna och att utvärdera den befintliga utgjutningssystemet. Mätningar för undersökningen är utförda i SAs smältverk, vid processtegen raffinering och utgjutning.

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27

Sundermann, Christoph. "Analyse des elektrochemischen Potentialrauschens zur Untersuchung des korrosiven Angriffs auf dünne Schutzschichten am Beispiel von Kohlenstoff auf Aluminium." [S.l. : s.n.], 2003. http://archiv.ub.uni-marburg.de/diss/z2003/0473/.

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28

Anyalebechi, P. N. "The solubility of hydrogen in pure aluminium and binary aluminium-lithium alloys." Thesis, Brunel University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.354569.

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29

Goodhand, Christopher James. "Hot working and recrystallization of high purity aluminium and aluminium 1% magnesium." Thesis, University of Sheffield, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245643.

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30

Al-Jumaili, Omar Saad Salih. "Investigation of friction stir welding of aluminium alloy and aluminium matrix composites." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/55637/.

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Friction stir welding (FSW) is an upgraded version of the conventional friction welding process, and it is considered the latest development and the most important one during the past two decades in the welding of metals. The dependence of FSW on friction and plastic work as a heat source precludes the melting in the workpiece and leads to avoiding many of the difficulties arising from the change in the state of the material, such as defects, distortion and residual stresses, which often happen in conventional welding processes. FSW gained significant attention as a solid-state welding process of aluminium alloys, but now there is a need to extend its application to advanced materials such as metal matrix composites (MMCs). However, the process has always represented a challenge owing to the complexity of microstructural development and the associated number of process parameters to take into consideration. This thesis investigates the feasibility of welding two new advanced aluminium matrix composites (AMCs), AA 6092/SiC/17.5p-T6 and AA 6061B/SiC/20p-T1 by FSW for the first time. Also, aluminium alloy AA6082-T6 has been investigated as base-line material to specify the benefit, drawback, and FSW window. Experiment analyses were conducted to evaluate the influence of FSW parameters, including tool rotation and traverse speeds on the quality of weldments. Weld joints were characterised in terms of thermal history, metallurgical behaviour, mechanical properties, and residual stresses. The metallurgical characterisations have been done by optical, scanning electron microscopy (SEM), electron backscattered diffraction (EBSD), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS). Microhardness, tensile, and low-cycle fatigue (LCF) test with the axial total strain-amplitude control mode R=ε_min⁄(ε_max=-1) were used for evaluating the mechanical properties. The results showed that the generated peak temperature in the welding joints is affected more significantly by the rotating tool speed, while the exposure time and subsequent cooling rate are controlled by tool traverse speed. The microstructure of nugget zone (NZ) exhibits an elliptical shape with a substantial grain refinement resulted from continuous dynamic recrystallisation (CDR) process with an increase in the fraction of high angle grain boundaries (HAGBs). The evolved grain size was greatly influenced by weld pitch as the ratio between tool traverse speed to tool rotation speed, which is a key parameter to control the amount of heat input, exposure time and cooling rate. In addition, in the case of AMCs more homogeneous distribution of reinforcement particles (SiC) coupled with particle refinement were formed in the NZ. The cross-weld microhardness proﬁle revealed a signiﬁcant difference in microhardness among the base metals, heat affected zone (HAZ), thermo-mechanically affected zone (TMAZ), and NZ in the case of AA 6082 and AMC (AA 6092/SiC/17.5p), as they depend on the strengthening precipitate. Meanwhile, the hardness profile of AMC (AA 6061B/SiC/20p) FSW joints showed that there is no difference in the measured hardness between the welding zone and base materials because the welded joints are exposed to thermal history similar to the initial heat treatment condition of the base metal, T1, cooled from an elevated temperature shaping process and naturally aged. The tensile strength of AA6082, and AMC (AA 6092/SiC/17.5p) cross-weld FSW specimens was found to be lower than their base metals with a joint efficiency (the ratio of the tensile strength of joint to the tensile strength of base metal) of about 71 and 75 %, respectively. While for SAMC (AA 6061B/SiC/20p) FSW joints it is reached 108 % of that of the base metal. The low-cycle fatigue results indicate that the fatigue life of the cross-weld joints varies with grain size in the NZ, and it is always lower than that of the base metal. A significant improvement in fatigue life is found to be related to the finer equiaxed grains dominated by HAGBs in the NZ, as well as, to less gradient in the grain size of the cross-weld. Residual stresses are significant concerns associated with the welding process, as it can combine with applied stresses, which may lead to the reduction of structural properties. The result of residual stress measurement by neutron diffraction techniques exhibited a typical ''M'' profile, which indicates that compressive and tensile residual stress existed in the base metal and welding zone, respectively. This has not only provided an improved understanding of residual stresses in FSW joints but also has contributed to the validation of 3D fully coupled thermo-mechanical finite element (FE) model, which has been developed based on Coupled Eulerian-Lagrangian (CEL) technique. The model is also used to predict the thermal history and material flow in the FSW of aluminium alloy AA6082. The numerical results showed a good agreement with the experimental results.

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31

Mercier, Sylvie. "Réactivité interfaciale de systèmes aluminium-fibres de carbone et aluminium-fibres céramique." Mulhouse, 1994. http://www.theses.fr/1994MULH0303.

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L'objectif de l'étude est d'apporter une contribution à la compréhension des phénomènes interfaciaux qui interviennent lors de l'élaboration des matériaux composites à renfort fibreux et à matrice aluminium. Les renforts choisis pour cette étude ont été des fibres de carbone, des fibres de carbone protégées, et des fibres à base de carbure de silicium. Ces fibres sous forme de tissu ont été recouvertes d'aluminium par dépôt physique en phase vapeur. Les matériaux ainsi obtenus ont subi des traitements thermiques dans un réacteur couple à un spectromètre de masse. L'existence de réactions entre certains gaz produits par les fibres (CO, CO2) et l'aluminium lorsque la température est supérieure à 650°C a ainsi pu être mise en évidence. Ces réactions se produisent lors de la traversée du dépôt d'aluminium par les gaz issus des fibres et provoquent la formation de carbone d'aluminium. Le carbure d'aluminium est également formé par des réactions entre les espèces solides constituant les fibres et le métal. La quantité de carbure d'aluminium formé à l'interface fibre/métal lors des traitements thermiques a été déterminée par hydrolyse. Il a ainsi pu être montré que le carbure d'aluminium provient essentiellement des réactions entre les solides constituant les fibres et le métal. L'efficacité de divers recouvrements contre la formation de carbure d'aluminium a aussi été étudiée.

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32

Urbanczyk, Robert, Kateryna Peinecke, Michael Felderhoff, Klaus Hauschild, Wolfgang Kersten, Stefan Peil, and Dieter Bathen. "Aluminium alloy based hydrogen storage tank operated with sodium aluminium hexahydride Na3AlH6." Elsevier, 2014. https://publish.fid-move.qucosa.de/id/qucosa%3A36284.

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Here we present the development of an aluminium alloy based hydrogen storage tank, charged with Ti-doped sodium aluminium hexahydride Na3AlH6. This hydride has a theoretical hydrogen storage capacity of 3 mass-% and can be operated at lower pressure compared to sodium alanate NaAlH4. The tank was made of aluminium alloy EN AW 6082 T6. The heat transfer was realised through an oil flow in a bayonet heat exchanger, manufactured by extrusion moulding from aluminium alloy EN AW 6060 T6. Na3AlH6 is prepared from 4 mol-% TiCl3 doped sodium aluminium tetrahydride NaAlH4 by addition of two moles of sodium hydride NaH in ball milling process. The hydrogen storage tank was filled with 213 g of doped Na3AlH6 in dehydrogenated state. Maximum of 3.6 g (1.7 mass-% of the hydride mass) of hydrogen was released from the hydride at approximately 450 K and the same hydrogen mass was consumed at 2.5 MPa hydrogenation pressure. 45 cycle tests (rehydrogenation and dehydrogenation) were carried out without any failure of the tank or its components. Operation of the tank under real conditions indicated the possibility for applications with stationary HT-PEM fuel cell systems.

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Olivo, Garrido Nikole, and Magendran Kajenta Lina. "Jämförelse mellan hjälpramar av aluminium och stål." Thesis, KTH, Hållbar produktionsutveckling (ML), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-281950.

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Hjälpramar konstrueras med olika profiler, utformningar och material för att kunna få den bästa möjliga funktionen. Syftet med följande arbete är att fastställa vilket av materialet stål och aluminium som är mest optimal vid tillverkning av hjälpramar för lastbilar. Arbetet genomfördes med hjälp av datainsamling för respektive material, och intervju med Henrik Sieurin från AluCar. Hållfasthetsberäkningar och FEM-analys på Creo utfördes för att studera hur respektive materialkomponent påverkas under påkänningar. Genom tillämpning av Pughmatris drog slutsatsen om vilket av materialet som är mest lämplig inom ekonomisk, miljö, hållfasthet, och säkerhet. Utifrån Pugh-matrisen bestämdes att aluminium är ett bättre material till användning för hjälpramar. En bra slutsats kunde inte utföras på grund av otillräckliga fakta inom planering, tillverkningskostnad, bearbetning och brist på värde. Dem här faktorerna kan påverka det slutliga resultatet.

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34

Fitz, T. "Ion nitriding of aluminium." Forschungszentrum Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-29382.

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35

Johnsen, Bernt Brønmo. "Adhesive bonding of aluminium." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Engineering Science and Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-515.

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In order to get approval of adhesive bonding as a reliable joining method in the automotive industry, a better understanding of the interfacial interactions between aluminium surfaces and adhesives is important. It is also important to get a better understanding of the degradation mechanisms of the bonded systems in humid environments, as humidity is known to have a detrimental effect. This work has been focused on an aluminium alloy and a one-component epoxy adhesive that are of particular interest to the automotive industry.

Pretreatment of the aluminium substrates before adhesive bonding is essential. However, the most successful pretreatment processes involve the use of hexavalent chromium, which will be banned from use within few years due to environmental considerations. Alternative pretreatments need to be developed. A literature study identified silanisation with GPS as a pretreatment method with the potential to obtain good durability. On the basis of research performed by SINTEF Materials Technology, AC anodising in hot phosphoric and sulphuric acid solutions were also identified as interesting pretreatment methods.

A modified version of the Boeing wedge test was used to determine the durability of adhesively bonded joints tested in hydrothermal environments. The joints were made of AA6060-T6 aluminium alloy and Betamate XD4600 epoxy adhesive. Both silane films and anodic oxides were investigated using reflection-absorption FT-IR spectroscopy. Other techniques of surface analysis were also used (SEM, TEM, WLI, XPS, ToF-SIMS and contact angle measurements).

The environmental durability of pretreated AA6060-T6 substrates was significantly improved after silanisation with GPS. The grit-blasting + GPS pretreatment process resulted in considerable higher durability then the chromic-sulphuric acid FPL-etch. The general understanding is that silanisation improves the durability through the formation of strong, covalent bonds between the aluminium surface and the adhesive. FT-IR spectroscopy strongly indicated that a chemical reaction took place between GPS films and amine curing agents. Particularly interesting was the reaction with dicyandiamide, which is a common curing agent in one-component epoxy adhesives. The amines also catalysed the condensation of SiOH groups, resulting in higher degree of SiOSi crosslink density in the siloxane films. However, chemical reaction is not necessary for improved durability. The hydrophobicity of the bonded surface is also an important factor. This effect has not been studies extensively earlier.

Exposure of GPS films to degrading environments showed that the silane desorbed from the surface in acidic solutions, but it was stable in alkaline solutions. The durability of adhesive joints was also reduced in acidic environments. The two models for the degradation of the silanised aluminium surface in acidic environments were proposed: hydrolysis of the siloxane network and corrosion of the underlying aluminium surface.

The environmental durability of substrates that were AC anodised in hot phosphoric and sulphuric acid solutions was good, almost as good as the well-established FPL + PAA pretreatment. DC anodising in sulphuric acid gave inferior durability. FT-IR spectroscopy showed that the anodic films formed in sulphuric acid contained significant amounts of sulphate. This can have a significant negative effect on the long-term properties of bonded joints. The anodic films released water during curing of the adhesive. The observations suggested that a transformation from the hydroxide to the oxide state took place.

Adhesive bonding in wet environment of substrates that were anodised in sulphuric acid had a negative effect on durability. The effect was more pronounced for DC anodised, than for AC anodised substrates. Bonding in wet environment also resulted in changed adhesive properties close to the oxide surface. Very little thixotropic agent was present in a ~200 nm wide region in the adhesive. This was explained by desorption of water from the oxide during curing of the adhesive.

Papers II, V and VI are reprinted with kind permission of Elsevier, sciencedirect.com.

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36

Organ, Robert Michael. "The electrograining of aluminium." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239518.

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Salter, Victoria Clare. "Anodic processes on aluminium." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387987.

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38

Oki, Makanjuola. "Conversion coatings on aluminium." Thesis, University of Manchester, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390302.

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39

Hughes, Phillipa Jane. "Cellular responses to aluminium." Thesis, University of Liverpool, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262389.

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40

Gravil, Peter Anthony. "Dynamics of aluminium surfaces." Thesis, University of Liverpool, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240749.

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41

Dray, A. E. "Diffusion bonding of aluminium." Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382557.

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42

Zhong, Zhen Chen. "Aluminium-based nanophase composites." Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627138.

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43

Bakir, Ayse. "Aluminium and breast cancer." Thesis, University of Reading, 2017. http://centaur.reading.ac.uk/72586/.

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Al-based antiperspirant salts have been implicated as a causative factor in the development of breast cancer due to their proximity of application to the upper outer quadrant of the breast where the majority of breast cancers originate. Since mortality results from metastasis of breast cancer, this thesis has investigated the effects of Al chloride and Al chlorohydrate at 10-4M and 10-5M concentrations on the migratory and invasive abilities of four human breast cell lines. 10-5M was chosen as the concentration of Al previously measured in human nipple aspirate fluids. Effects on migration and invasion of MCF-7, MDA-MB-231, MCF-12A and HMF-3A human breast cells were explored using time-lapse microscopy, wound-healing assays and xCELLigence technology. Molecular pathways involving MMP-9, MMP-2, MMP-14, TIMP-1, TIMP-2, TIMP-3, ferritin and NDRG-1 were studied using RT-PCR, western immunoblotting and gelatin zymography. Prior exposure to Al increased the motility of MCF-7 cells after 32 weeks, of MDA-MB-231 cells after 25 weeks of prior exposure and of MCF-12A cells after 11 weeks. At a molecular level, Al chloride and Al chlorohydrate at 10 -5 M and 10 -4 M concentrations affected MMP-9 and MMP-14 mRNA and protein levels in MCF-7, MDA-MB-231 and MCF-12A cells. Although Al did not alter the motility of HMF-3A cells, changes in MMP-9, MMP-2 and MMP-14 mRNA expression and MMP-14 protein levels were found. Levels of the MMP inhibitors, TIMP 1, 2, and 3 were altered in MDA- MB-231 cells. Changes were observed in TIMP-3 levels in MCF-12A cells and TIMP-2 expression in HMF-3A cells. In considering the effects of Al on iron homeostasis, Al chloride was found to enhance ferritin levels in MCF-7 cells after 27weeks and in MCF-12A cells after 1week. Al chlorohydrate increased ferritin levels in MDAMB-231 cells after 21weeks. NDRG-1 mRNA and protein levels in MCF-7, MDA-MB-231 and MCF-12A cells were also affected but only NDRG-1 mRNA was altered in HMF-3A cells. Overall, it can be concluded that Al salts increase migration and invasion of human breast epithelial cells irrespective of whether they are transformed (MCF-7, MDA-MB-231cells) or not (MCF-12A cells), and irrespective of whether the cancer cells are oestrogen responsive (MCF-7 cells) or not (MDA-MB-231 cells). The changes observed in the levels of MMP-2, MMP-9 and MMP-14 and their inhibitors are indicative of a potential molecular pathway. The results demonstrate that exposure to Al chloride can increase ferritin levels, implicating alteration to iron homeostasis which is a known factor in the development of breast cancer. The results also showed that NDRG-1 expression, whose increase may depend on cell stress as for nickel, may not cause alterations observed in migration and invasion. In the light of these findings, it can be concluded that Al has mechanistic potential to cause metastatic tumour spread, which is the major reason for breast cancer mortality.

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44

Park, Sungbae. "Rheocasting of aluminium alloys." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670041.

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45

Fitz, T. "Ion nitriding of aluminium." Forschungszentrum Rossendorf, 2002. https://hzdr.qucosa.de/id/qucosa%3A21765.

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46

Bou, Madeleine. "Adhésion polyéthylène-téréphtalate-aluminium." Ecully, Ecole centrale de Lyon, 1991. http://www.theses.fr/1991ECDL0015.

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L’étude de l'adhésion et de l'adhérence d'une couche d'aluminium (al) déposé par évaporation thermique sur un film polyéthylène-téréphtalate (pet) a été entreprise. Nous avons utilisé la spectroscopie des photoélectrons et la microscopie électronique en transmission pour définir la physico-chimie de l'interface du couple al/pet et le tribomètre sous ultra-vide pour tester la tenue mécanique du film al. La métallisation a été réalisée à 10##7pa, sur deux types de films : biétiré et amorphe. Les résultats ont montre que la conformation superficielle n'influait pas sur les phénomènes physico-chimiques. Ces deux films présentaient la même réactivité vis-à-vis des atomes d'aluminium. Les premiers atomes d'aluminium déposés ont réagi chimiquement avec le polymère. Les premiers sites réactifs sont les groupements carbonyles. Ceci est corrobore par un modèle de mécanique moléculaire. Les réactions chimiques ont provoqué la formation de compose de type c-o-al puis c-al. Le composé c-o-al a été interprété comme un complexe a transfert de charges, provenant d'une réaction du type acide-base, sans rupture de chaine du polymère. Les noyaux aromatiques, second sites réactifs, ont contribué à la formation de c-al, laquelle pouvant être retardée par la présence de l'oxygène. Nous avons également mis en évidence l'influence du vide sur l'épaisseur de la couche interraciale ainsi que sur la microstructure de la couche métallique. La métallisation a 10##7pa permet d'obtenir une interphase mixte et une couche métallique constituée de gros grains alors que la métallisation en présence d'oxygène (10##3pa) donne une interface abrupt et une couche formée de grains plus fins. Les essais de frottement sous ultra-vide et l'étude microscopique du film dégradé montrent que l'existence de l'interphase est plus bénéfique car elle permet le relâchement des contraintes donc une meilleure tenue mécanique du film dans ce genre de test

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47

Sliwinski, Peter R. "Powder painting of aluminium." Thesis, Aston University, 1985. http://publications.aston.ac.uk/14478/.

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The mechanisms involved in the production of chromate-phosphate conversion coatings on aluminium have been investigated. A sequence of coating nucleation and growth has been outlined and the principle roles of the constituent ingredients of the chromate-phosphate solution have been shown. The effect of dissolved aluminium has been studied and its role in producing sound conversion coatings has been shown. Metallic contamination has been found to have a dramatic influence on chromate-phosphate coatings when particular levels have been exceeded. Coating formation was seen to be affected in proportion to the level of contaminaton; no evidence of sudden failure was noted. The influence of substrate and the effect of an acidic cleaner prior to conversion coating have been studied and explained. It was found that the cleaner ages rapidly and that this must .be allowed for when attempting to reproduce industrial conditions in the laboratory. A study was carried out on the flowing characteristics of polyester powders of various size distributions as they melt using the hot-stage microscopy techniques developed at Aston. It was found that the condition of the substrate (ie extent of pretreatment), had a significant effect on particle flow. This was explained by considering the topography of the substrate surface. A number of 'low-bake' polyester powders were developed and tested for mechanical, physical and chemical resistance. The best formulation had overall properties which were as good as the standard polyester in many respects. However chemical resistance was found to be slightly lower. The charging characteristics of powder paints during application by means of electrostatic spraying was studied by measuring the charge per unit mass and relating this to the surface area. A high degree of correlation was found between charge carried and surface area, and the charge retained was related to the powder's formulation.

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48

Cai, Fanglin. "Conception et analyse mécaniques des pièces en aluminium pour application automobile /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2007. http://theses.uqac.ca.

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Thèse (M.Eng.) -- Université du Québec à Chicoutimi, 2007.
La p. de t. porte en outre: Mémoire présenté à l'Université du Québec à Chicoutimi comme exigence partielle de la maîtrise en ingénierie. CaQCU Bibliogr.: f. 140-143. Document électronique également accessible en format PDF. CaQCU

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49

Matbou, Riahi Mehran. "Numerical and experimental studies of the mechanical behaviour at the ice/aluminium interface = Études numérique et expérimentale du comportement mécanique à l'interface glace/aluminium /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2007. http://theses.uqac.ca.

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Thèse (M.Eng.) -- Université du Québec à Chicoutimi, 2007.
La p. de t. porte en outre: Mémoire présenté à l'Université du Québec à Chicoutimi comme exigence partielle de la maîtrise en ingénierie. CaQCU Bibliogr.: f. 137-143. Document électronique également accessible en format PDF. CaQCU

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50

Chen, Hu. "L'effet du taux de refroidissement, modification au strontium, traitement thermique du liquide et la mise en solution sur les caractéristiques des particules du silicium eutectique et les propriétés de traction de l'alliage A356 /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2005. http://theses.uqac.ca.

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Dissertations / Theses on the topic 'Aluminium (Al)'

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